Inverted Fate: An Angel Fallen From Heaven

Frisk is the protagonist of Inverted Fate. They are a human with a red SOUL. Despite their strong determination and experiences in the previous world, they remember almost nothing of it beyond hazy déjà vu. Frisk is non-binary and uses they/them pronouns.

HISTORY

Frisk never knew their birth parents and grew up in an orphanage, where they often felt overlooked and unwanted. Though the caretakers were not abusive, the constant cycle of young residents coming and going left Frisk feeling invisible. Their one true constant was a girl named Lilac, whom they became very close to.

Inspired by Lilac’s ability to smile through hardship, Frisk tried to do the same. The two often snuck out together and got into trouble—stealing snacks, pulling reckless stunts, and generally earning Frisk a reputation as a troublemaker. Beneath the mischief, though, Frisk desperately wanted belonging and someone who would truly care about them.

Eventually, Frisk came up with a reckless plan: disappear at Mt. Ebott so people would finally notice them. Lilac agreed at first, but backed out at the last minute, frightened by the danger. In a moment of anger, Frisk lashed out and struck her, causing her to fall and suffer serious injuries. Though she survived, Frisk never got the chance to apologize.

That moment haunted them. Since then, Frisk has dreaded fighting and developed a deeply negative self-image, hiding it behind forced cheer, confidence, and a desire to seem “cool.” When life on the surface continued to leave them isolated, they returned to Mt. Ebott and fell Underground.

The Underground became the best thing that ever happened to them. There, Frisk found monsters who genuinely cared and began building real friendships. In the original timeline, they struggled at first—feeling smothered by Toriel, killing Undyne when they couldn’t find another way past her, then resetting out of guilt after Papyrus called wanting everyone to spend time together. Eventually, they found a better path, spared Flowey, and neared a Pacifist ending... until Asriel entered his second form and killed them while trying to take their SOUL.

Their SOUL did not refuse.

The timeline reset. Six monsters swapped fates, the Underground changed, and Frisk’s journey began again—only this time, they remembered none of it beyond faint déjà vu.

APPEARANCE

Frisk is fairly short and scrawny, with messy shoulder-length brown hair. Due to their myopia, they usually squint, giving them their trademark closed-eye look, though their eyes are brown when fully visible. While their sprite is often yellow-toned, their canonical skin tone is tan.

Their outfit changes by area:

•	Surface/Ruins: worn blue shirt with magenta stripes and blue pants.
•	Snowdin: purple hoodie with fuzzy trim, matching beanie, black mittens and boots, tan snow pants.
•	Waterfall: Sans’ old hoodie, a “bonedanna,” and Papyrus’ padded pink COOL KID shirt, while keeping the Snowdin winter gear.
•	Hotland: shorts and sneakers, keeping the COOL KID shirt.

PERSONALITY

Frisk tries hard to come across as friendly, confident, cool, and outgoing. They’re eager to make friends, quick with sassy quips and bad puns, and can be a playful smartass without being cruel. Their teasing and flirting usually come from a place of affection.

They’re naturally curious and observant, often poking into anything suspicious or unusual. Though friendly, they aren’t naïve and can be nosy, skeptical, and willing to call out behavior they don’t trust.

Like Papyrus, Frisk is deeply insecure. They want to feel important, wanted, and loved, which makes them vulnerable to manipulation—especially when someone offers them the recognition or affection they crave. They have a bad habit of denying uncomfortable truths when things seem to be going their way, latching onto kindness quickly and trusting people they want to believe in.

At heart, Frisk is somewhat selfish, though they hate that about themself. They genuinely care about others, but they also desperately want that care returned. This need, combined with their self-loathing, makes them emotionally messy and easy to shake when their optimism cracks.

Though mostly pacifistic, Frisk can be stubborn, grouchy, and mean when pushed. They dwell heavily on their mistakes and struggle to let things go. In many ways, they’re a pessimist pretending to be an optimist—and so far, that act is what’s kept them going.

⸻

Chara is a major character in Inverted Fate. A passenger within Frisk’s body, they narrate Frisk’s actions and gradually become more open and personal with them over time.

HISTORY

Chara was born in the 21st century as the unwanted offspring of an affair between two wealthy elites. Kept only out of obligation, they grew up unloved and were repeatedly made to feel like a mistake. Around age ten, they ran away and eventually reached Mt. Ebott, becoming the first human to fall Underground.

Though injured, Chara survived the fall and was found by Asriel, who helped them and asked their name. In that moment, they abandoned their birth name and chose “Chara.” Soon after, they were taken to the Dreemurr family, who welcomed and loved them as one of their own.

Chara and Asriel grew especially close, exchanging heart lockets as symbols of their bond. However, tragedy eventually followed. One of the best-known incidents was the infamous buttercup pie accident that made Asgore ill—an event Chara laughed off even as Asriel and Toriel were upset.

Over time, Chara’s plan to use their own death and Asriel’s power to collect human SOULs led to catastrophe: both of them died, and the Dreemurr family was torn apart. In the current timeline, the remains of Chara’s SOUL became fused with Frisk’s, leaving them as a voice in Frisk’s head. They can be heard by Frisk and certain ghosts, and later gain a visible ghostly talksprite during the CORE arc. They can also feel what Frisk feels and have occasionally taken control, though they try to avoid doing so.

When Frisk and Chara’s combined SOUL is split, Chara briefly gains a temporary red “SOUL-projection” form resembling how they looked in life.

APPEARANCE

Before death, Chara was a short, scrawny youth who strongly resembled Frisk: messy shoulder-length brown hair, a similar build, and similar fashion. However, they were not identical. Chara had lighter skin, typically open eyes, and a constant pink blush on their cheeks. They wore a green sweater with a yellow stripe, tan pants, and brown boots.

As a ghostly presence within Frisk, they are usually unseen, though later they appear as a transparent version of their living self. Their temporary SOUL-projection form resembles their original body, but shaded in red.

PERSONALITY

Chara is cynical, sarcastic, and pretentious. They remember the original timeline in full and have grown even more bitter knowing Flowey’s true identity.

Because of their loveless upbringing, Chara initially hated humanity and despised Frisk. At first, they only guided Frisk because Frisk’s pain affected them too. Over time, however, they grew attached, gradually speaking to Frisk more directly and personally instead of remaining a detached narrator.

As their bond deepens, Chara’s views on humanity begin to change. Frisk becomes, in their own words, proof that there is good in humanity.

Chara is also weighed down by immense guilt. They blame themself for pushing Asriel into their plan, getting them both killed, and destroying the Dreemurr family. Their self-worth is extremely low, and they react badly to anyone trying to defend or glorify their past actions. When Mettaton publicly defends them and unveils a statue in their honor, Chara is so disturbed that they possess Frisk to reject the praise, even at the cost of revealing themself.

———

Papyrus is the deuteragonist of Inverted Fate and the royal scientist’s aide. He joins Frisk in Snowdin as both a close companion and party member.

HISTORY

Papyrus grew up in the Capital with his brother Sans and their father. When he was very young, his father died, leaving Sans as his guardian. Sans briefly took over as Royal Scientist before resigning, and the brothers moved to Snowdin, which Papyrus found difficult to adjust to.

As a child, Papyrus got lost in Snowdin Forest and was found by Asgore, disguised as Santa Claus. Asgore comforted him, let him help deliver presents in town, and became a lasting father figure in his life. From then on, Papyrus often visited the Ruins Door to speak with him. Asgore helped shape Papyrus’ views on humanity, encouraged his compassion, and later asked him to protect Frisk. He also sparked Papyrus’ interest in botany.

After Sans left to train for the Royal Guard, Undyne became Papyrus’ babysitter. The two quickly bonded, and her inventions and ambition inspired Papyrus to see science as something exciting and meaningful. When Toriel later appointed Undyne as Royal Scientist after her creation of Snowdin’s holo-sky, Papyrus became determined to follow in her footsteps, eventually earning a place as her assistant.

Papyrus also befriended Mettaton during this time. Alongside Undyne, he helped conduct experiments involving human SOULs and determination in hopes of finding a peaceful way to break the Barrier. While Undyne worked on a mechanical vessel for the SOULs, Papyrus focused on golden flowers. One of these experiments created this timeline’s Flowey—the “flower born from the ashes.” Though initially lifeless, Papyrus cared for it deeply before giving it to Asgore, who planted it in the Ruins. He and Undyne also experimented on fallen monsters, though Undyne pushed their determination research much further than Papyrus realized.

APPEARANCE

Papyrus is a tall, slender skeleton wearing a bright red cape, matching mittens and boots, and a white lab coat over his usual “battle body.” He also wears crimson goggles on his head, usually resting on his forehead. His skull is highly expressive despite being skeletal, and when especially excited, he sprouts BIG, GOOGLY EYES and can even sweat or blush.

PERSONALITY

Papyrus is loud, enthusiastic, cheerful, and endlessly eager. He boasts about his greatness—his inventions, cooking, puzzles, and genius—but beneath the bravado, he is deeply kindhearted and always ready to befriend and encourage others.

He genuinely wants to improve life for Snowdin’s monsters through his inventions, though his ambition often leads to bizarre or impractical results: inconvenient puzzles, suspicious glowing spaghetti, or even exploding escalators. He’s eccentric, inventive, and wildly ambitious, the type to create pocket dimensions for sock disposal, interdimensional portals to meet alternate Papyruses, and “COOLCULATIONS” purely because they’re cool.

Despite his quirky nature, Papyrus is not as oblivious as he seems. He understands the harsh reality of the Barrier, the need for seven human SOULs, and the growing resentment toward humanity. Still, his idealism refuses to let him judge humans before giving them a chance. This belief is one of the key reasons he joins Frisk.

Underneath it all, Papyrus carries deep insecurities. He envies how Snowdin admires Sans and how monsterkind looks to Undyne as a symbol of hope. Though some respect his efforts, he has few close friends and often masks his loneliness behind a smile. He is desperate to make others happy, even when their desires conflict, which leaves him under constant stress. Even so, he refuses to give in to despair, channeling his fears into hope, hard work, and determination.

He also knows far more than he lets on.

⸻

Flowey the Flower is the main antagonist of Inverted Fate. As Asriel, God of Hyperdeath, he accidentally created the alternate timeline in which the story takes place. Intrigued by this, he adopts a new strategy: presenting himself to Frisk as a friend and involving Papyrus in his plans.

HISTORY

In canon Undertale, Flowey was created when one of the golden flowers in Asgore’s garden was injected with determination after being dusted with Asriel’s remains. In Inverted Fate, however, the flower vessel was created by Papyrus during his and Undyne’s determination experiments. Because of this, Papyrus trusted Flowey quickly once he revealed himself, much to Flowey’s amusement—and confusion.

APPEARANCE

Flowey looks identical to his canon self: a sentient golden flower with six bright yellow petals, a light-green stem, and a face capable of twisting into grotesque expressions.

Redesigned Flowey: After absorbing the six human SOULs, his appearance permanently changes to fit the altered timeline. His stem and petals become more detailed, his grin widens to reveal both rows of teeth, his eyes sit farther apart and are vertically wider, and two vine/root tips appear near his body. He keeps his general color scheme and expressive face. This is also the form he reverts to if he gives up the soul’s.

“God of Hyperdeath” form: After absorbing the monster souls as well, Asriel adopts a new version of this form. He retains the black sclerae, fangs, robe, and Heart Locket from canon, but now has black hair with jagged bangs (“emo hairstyle”), black gauntlets, and a purple cape.

PERSONALITY

Flowey is highly intelligent, manipulative, and deeply self-serving. He has little regard for anyone’s safety or well-being beyond his own, and his hunger for power drives him to extreme lengths.

He can be hypocritical—most notably warning Frisk and Papyrus that Sans is “shady and untrustworthy” while being exactly that himself. As an ally, he is unreliable and exploitative, taking advantage of Frisk’s vulnerable state after the accidental amalgamation of Undyne and Mettaton in order to secure the human SOULs for himself.

⸻

Sans is Papyrus’ older brother and a supporting character in Inverted Fate. He is lieutenant of the Royal Guard and the final boss of Snowdin, though he remains a recurring presence throughout the story.

HISTORY

Sans grew up in the Capital with Papyrus and their father, Dr. W.D. Gaster. As a teen, he worked alongside Gaster and hoped to follow in his footsteps. During the unveiling of a new machine designed to empower monster SOULs, disaster struck: the machine overloaded and threatened to send the CORE into meltdown. Gaster refused to leave, forcing Sans to choose between risking everyone or destroying the machine. He chose to save the CORE, firing a Gaster Blaster at the machine and losing his father in the process.

Shortly after, he met a young Undyne, whose energetic personality distracted him from his grief. He took her on as an apprentice, and at only fifteen, he was thrust into the role of Royal Scientist while also caring for Papyrus.

Though he tried to continue Gaster’s work, he could never repair the machine. The pressure, grief, and guilt eventually became too much, and he gave up the lab coat. Seeking a fresh start, he unexpectedly joined the Royal Guard, impressing Toriel and Gerson with his Gaster Blasters during tryouts. He quickly befriended fellow trainee Alphys, and the two rose through the ranks together.

When Gerson retired, he offered Sans leadership of the Guard, but Sans turned it down in favor of Alphys, believing she earned it and knowing he didn’t want that level of responsibility. Instead, he became her right-hand man and commander of the Canine Unit.

Meanwhile, Papyrus took up science in his place. Sans supported him, but when Undyne’s determination experiments began going too far, it created a lasting rift between them. Growing suspicious, he even asked Mettaton to keep an eye on Papyrus and Undyne as a precaution.

APPEARANCE

Sans is an extremely short and big-boned skeleton. Papyrus made his usual outfit: a neatly wrapped blue striped scarf, blue mittens, a short-sleeved blue jacket with a Delta Rune badge, blue boots, and a white shirt with the Starman emblem.

Early in the comic, he switches to a golden suit of armor while keeping the vest, scarf, and boots. The armor bears the Delta Rune, emphasizing his role in the Royal Guard.

PERSONALITY

Sans is laid-back, social, and fond of bad puns and pranks. He seems to know everyone in the Underground and can chat comfortably with almost anyone. Beneath the lazybones act, though, he is observant, sharp, and constantly thinking. Like his canon counterpart, he is especially skilled at reading expressions and piecing together what people aren’t saying.

Despite appearances, he isn’t truly lazy. As Snowdin’s guard, he takes his duty seriously and genuinely wants to keep its monsters safe. His teleportation lets him scout quickly, which is how he gets away with naps and breaks. He also deliberately leans into the harmless slacker image so real threats underestimate him—never expecting someone like him to be hiding Gaster Blasters and other dangerous tricks.

Sans fights smart rather than hard. Raised knowing humans can overpower monsters with enough hate, he relies on misdirection, rule-bending, and efficiency rather than brute force. His guard training gives him strength, but he prefers strategy.

Emotionally, Sans keeps most of himself locked away: his regrets, grief, worries about Papyrus, the truth behind abandoned dreams, and the fear of what another human means for the Underground. With monsterkind growing desperate for freedom, the Royal Guard has shifted from defense toward preparing for the final human’s arrival, placing pressure on him, Alphys, and Toriel alike. Now that a human has arrived—and Papyrus has befriended them while keeping secrets—his stress has only grown.

At heart, Sans is cynical, though he hides it behind humor and an easy smile. He wants to believe in Papyrus and in a peaceful outcome, but experience has taught him life rarely works that way. He’s made compromises he hates, and while he avoids promises and commitment, he’ll cast all of that aside for Papyrus. Almost everything he does is for his brother’s sake.

———

Asgore Dreemurr is the former king of the Underground. He now lives in the Ruins, where he seeks to atone for his past and make life better for its residents.

HISTORY

Long before Frisk fell Underground, Chara was adopted by the Dreemurr family, bringing hope that humans and monsters might one day coexist peacefully. But that hope ended when Chara fell ill and died, followed soon after by Asriel, who returned transformed after absorbing Chara’s SOUL and then died in front of his parents.

Consumed by grief and rage, Asgore declared war on humanity, vowing to kill any human who fell and use their SOULs to break the Barrier and destroy humanity. Toriel opposed him, but when another human appeared, Asgore fought them repeatedly through multiple RESETs. Though he could not remember the loops, the repeated battle wore on him. Once the child finally gave up, Asgore claimed their SOUL—but the guilt of killing another child broke his resolve.

Soon after, he vanished from the palace and retreated to the Ruins, ashamed of what he had done. There, he chose a different path: helping fallen children instead of harming them, preparing them for the world beyond and trusting Toriel to shelter them if they reached her. He also dedicated himself to improving life in the Ruins, becoming a warm, hopeful presence for its residents.

Over the years, humans and monsters came and went, and some monsters even chose to settle in the Ruins. Asgore grew close to Napstablook and Papyrus, the latter of whom he first met as a child while disguised as Santa Claus. He became a mentor figure to both, encouraging Papyrus’ compassion, gardening, and hopeful view of humanity.

After the Determination Experiments and the release of the Dreemurr tapes, Asgore asked Papyrus to help protect any future fallen humans. Too ashamed to leave the Ruins himself, he believed Papyrus could be the one to guide and inspire them. Papyrus agreed without hesitation.

APPEARANCE

Asgore is a towering white goat-like monster with large horns, floppy ears, golden hair, and a matching beard. He wears a hooded cloak that fastens around his horns and a Delta Rune pendant on his chest.

PERSONALITY

Asgore is warm, jolly, and endlessly kind, always eager to help, listen, and lift others’ spirits. He walks the Ruins often, socializing with residents, tending gardens, and making the area safer and more comfortable—removing spikes from puzzles, adding modern comforts, and cushioning dangerous spots. Once a year, he even leaves the Ruins disguised as Santa Claus to deliver gifts.

To most, he seems like one of the happiest monsters in the Underground. In truth, he is deeply burdened by guilt. He knows his hands are stained by the past, and much of his kindness is driven not just by generosity, but by a desperate need to atone. He no longer wants war or revenge. His hatred for humanity has long since faded.

All he seeks now is peace... and hope.

⸻

Alphys is the Captain of the Royal Guard and the final boss in Waterfall.

HISTORY

From a young age, Alphys was fascinated by humans—their history, media, and culture. She made regular trips to the dump to collect human artifacts, befriended Bratty and Catty like an older sister, and later became close with Mettacrit (future Mettaton), bonding over their shared love of humanity and even forming a human fanclub.

At sixteen, Alphys joined the Royal Guard in hopes of one day meeting humans face to face and maybe even becoming their hero. During tryouts, she met Sans, and the two gradually formed an awkward but effective friendship. When Gerson retired, Sans turned down leadership and recommended Alphys instead, making her Captain while he remained her lieutenant.

Later, Alphys met Undyne, an up-and-coming scientist whose technical brilliance immediately impressed her. The two bonded over anime, inventions, and mutual admiration, developing feelings for one another but never acting on them. At Mettacrit’s request, Alphys introduced him to Undyne, who eventually built him a robot body under strict conditions: he had to stay connected to his loved ones, not let fame consume him, and allow anti-human weaponry to be built in.

After the Dreemurr tapes reignited anti-human sentiment, everything changed. Mettaton was forced into the role of anti-human protector, and Alphys felt pressured to bury her true feelings about humans and become a colder, harsher leader. At the same time, Undyne grew more aggressive and desperate, causing a painful rift between them. Though they still cared for each other, Alphys began compromising her own values to become the kind of figure she believed the Underground—and Undyne—wanted.

APPEARANCE

Alphys is a short yellow lizard monster. When first introduced, she wears full metal armor with an intimidating mask featuring sharp spines, glowing yellow eyes, and metallic teeth. Underneath, she wears simple goggles that help with her poor vision.

Out of armor, she wears a pink Mew Mew Kissy Cutie shirt and tan pants.

PERSONALITY

At her core, Alphys is shy, awkward, anxious, and deeply insecure. On Royal Guard duty, she hides that behind a cold, quiet, intimidating persona, aided by the voice amplifier in her helmet.

She is intelligent, tactical, and the strategic mind of the Royal Guard, handling logistics, plans, and operations. However, she often leans on Sans in social situations due to his confidence and ease with others.

Beneath the armor, Alphys is passionate about anime, video games, human culture, and humans themselves—but in the current climate, she sees those interests as dangerous. With anti-human fear at an all-time high, she suppresses her true feelings to avoid being seen as a traitor. She wants to be respected and admired, especially by Undyne, and sacrifices pieces of herself in pursuit of that.

When Frisk arrives, though, her hesitation becomes obvious. She quietly gives Frisk and Papyrus chances to escape, knowingly allowing them openings to turn back instead of fully committing. Unlike Undyne, she lacks the conviction to follow through completely, and the false persona she forces herself to wear only deepens her inner conflict.

Since befriending Frisk, Alphys has begun realizing she needs to confront Undyne and finally admit how she really feels. But fear still holds her back.

⸻

Mettaton, formerly known as Mettacrit, is the Underground’s biggest celebrity and a human-eradication robot built by Royal Scientist Undyne.

He is a supporting character in Inverted Fate who helps Frisk and Papyrus while pretending to remain on Undyne’s side.

HISTORY

Mettaton is still the Underground’s superstar, though his shows now lean more heavily into action and anime themes. He hosts a variety of programs and even runs a streaming platform called Mettflix.

Undyne built his robot body as a favor to Alphys and because she wanted to help him achieve his dream. However, she only agreed after he promised to stay close to Napstablook and Shyren, who remain important parts of his life as costars and members of his sound team.

His body was also equipped with real anti-human weaponry, something Undyne insisted on so he could protect his fans and loved ones. Mettaton accepted because it was his chance to achieve his dream body.

As anti-human sentiment worsened, Mettaton was forced into the role of a flashy anti-human defender, catering to public expectations to protect his career. Though he continues the act, it has left him bitter and frustrated, forcing him to suppress both his true creative vision and his real feelings toward humanity.

APPEARANCE

Box Form: Mettaton is a gray box-shaped machine with a yellow screen, red shades that change with his emotions, and brown dials. He moves on a single spiked wheel and wears red spiked pauldrons and a cape.

SPIRAL Form: In SPIRAL form, Mettaton becomes a handsome, glamorous knight in flaming red-orange armor, retaining his large spiked pauldrons and wielding a fiery sword. He also wears transparent star-shaped glasses. Outside of battle, his flaming wings fold into a cape similar to his box form.

PERSONALITY

Mettaton is still dramatic, flashy, and larger-than-life, with constant brand promotion and theatrical flair. At first glance, he seems as egotistical as ever.

In reality, he is far more grounded than his canon counterpart. Because Undyne made him stay connected to his loved ones, he kept his friends and family close, which prevented his fame from fully consuming him. He is humbler, kinder, and more emotionally anchored, even if he still enjoys the spotlight.

Still, beneath the glamorous persona lies a jaded and lonely artist. Despite his massive fanbase, few people truly know him beyond the surface. He resents having to play the role of an anti-human icon and hates compromising his morals and creativity to keep his dream alive. That inner conflict is a major reason he secretly helps Frisk and Papyrus whenever he can.

He doesn’t truly hate Undyne—but he deeply resents the hateful world her actions helped create.

———

Queen Toriel is the official, though inactive, ruler of the Kingdom of Monsters. She is the mother of Asriel Dreemurr and the adoptive mother of Chara and later the Mage. Though she fought to preserve peace between humans and monsters, growing hatred in the Underground eventually drove her into seclusion.

HISTORY

Toriel once ruled the Underground alongside Asgore. Together, they raised their son Asriel and later adopted Chara. For a time, the future seemed hopeful—until Chara fell ill and died. Soon after, Asriel returned to the throne room transformed after absorbing Chara’s SOUL, only to collapse and turn to dust before his parents.

In his grief, Asgore declared war on humanity, enraging Toriel, who saw it as a betrayal of Chara’s memory. She tried to reason with him, but soon another human appeared, and Asgore returned with their SOUL. Unable to continue with his own plan, he abandoned the throne and fled to the Ruins, leaving Toriel to rule alone.

Toriel immediately rejected the war and insisted there would be no campaign against humanity. Public outrage followed, only quieted when she invoked Chara’s memory. To maintain peace, she ordered the Royal Guard to bring humans to her so they could be judged individually rather than killed on sight. She also pushed education reform, encouraging honest teaching about human history in hopes of reducing fear and hatred.

Some humans who fell were protected. Others were not so fortunate. Over time, tragedy continued to repeat itself—some fled, some fought, some died by violence or despair—and the collected SOULs became a growing burden on Toriel’s conscience. Even after one human lived out their full life under her protection, she was left grieving once more.

Still, she continued to rule as best she could. When Undyne proposed a way to break the Barrier without more human deaths, Toriel, desperate for another solution, granted her access to all six SOULs. She would come to regret it.

The failed experiments, combined with the release of the Dreemurr family tapes and the renewed wave of anti-human rage, finally broke her spirit. Seeing the Underground as too consumed by hatred to be saved, Toriel withdrew into the castle and vanished from public life.

She has not been seen in three years.

APPEARANCE

Toriel is a tall goat monster with red eyes. She wears a blue cloak over gray robes with large shoulder pads, a crown set with a blue gemstone, and carries a blue staff adorned with a flower. Her clothes are frayed at the edges.

PERSONALITY

Toriel strongly opposed Asgore’s war and took the throne after he fled. She tried to judge every fallen human fairly, even when that stance made her unpopular.

After the truth about her children was revealed through the tapes, her spirit shattered. The repeated losses, the failures of the kingdom, and the hatred of her people finally drove her into total isolation. Before the story begins, only Sans, Papyrus, and Alphys have spoken to her in the past three years.

⸻

Undyne is the royal scientist and secondary antagonist of Inverted Fate. She lives in Hotland and effectively rules the Underground in Toriel’s absence.

HISTORY

Undyne grew up in Forgespring, deep in Waterfall, where stories of human cruelty—especially the Waterfall Incident—shaped her view of humanity from a young age. Even so, knowing that the heroic Mage from that battle was also human left her conflicted.

When she was nine, the day of Dr. Gaster’s grand invention ended in disaster instead of celebration. Afterward, she encountered a grieving young Sans in a lab coat and mistakenly thought he was Gaster at first. Her barrage of questions marked the start of their relationship, and through him, she became fascinated by science. She eventually became Sans’ apprentice after he was forced into the role of Royal Scientist.

During her apprenticeship, Sans encouraged her never to give up—but she later realized he already had. When she asked about Gaster, he showed her only the ruined machine, offering no real explanation. Later, she also encountered strange gray monsters that hinted at darker truths.

After Sans abandoned science to join the Royal Guard, Undyne became Papyrus’ babysitter, and the two quickly formed a close friendship. Later, her ambitious creation of a holographic sky over Snowdin impressed Toriel so much that she was appointed the new Royal Scientist.

Over the following years, Undyne devoted herself to improving monsterkind’s lives. She befriended Alphys through their shared love of science, anime, games, and history, and through Alphys, she met Mettacrit, eventually building his robot body—with anti-human weaponry and strict conditions about staying connected to his loved ones. She later built Mad Mew Mew’s body as well.

Eventually, Undyne set her sights on her greatest goal: breaking the Barrier through science. She publicly promised the Underground that she would be the one to free them, a vow that slowly consumed her. Inspired by her, Papyrus became her assistant, and together they began the Determination experiments—Papyrus focusing on flowers, Undyne on a SOUL vessel mech. Somehow, Undyne also gained awareness of SAVEing and LOADING.

But Undyne pushed the experiments far beyond what Papyrus understood. Evidence suggests she injected herself with determination and relied on bandages, tubes, wires, and cybernetic replacements to stabilize her increasingly damaged body.

During this time, she discovered the Dreemurr tapes. Horrified by what she believed Chara had done, she played the tapes publicly despite Papyrus’ objections, reigniting anti-human hatred across the kingdom. Chara was widely recast as a demon who stole Asriel away. Combined with old grief from the Waterfall Incident, this pushed the Royal Guard into a harsher anti-human stance outside Snowdin and helped drive Toriel into total seclusion.

Meanwhile, the Determination experiments succeeded only in creating more suffering: fallen monsters awoke, then amalgamated. Undyne kept promising she would fix it, but the damage was done. Her actions fractured her relationships with Sans, Alphys, Mettaton, and even the wider Underground, leaving fear, hatred, and desperation in their wake.

By the time Frisk arrives, Undyne has fully committed to one terrible conclusion: when the next human falls, she will take the final SOUL herself—no matter the cost.

APPEARANCE

Undyne is a tall blue fish-like monster with messy red hair tied in a ponytail. She has one yellow eye and one robotic eye, sharp white teeth, and wears a long lab coat with a spiky red high collar. Beneath it, she wears blue jeans, red boots, and black gloves. Her face is the only part of her body left exposed.

PERSONALITY

Undyne is loud, aggressive, dramatic, and larger-than-life. She throws herself into everything with total passion and refuses to back down, driven by a fierce love for monsterkind and an equally fierce determination to free them. Over time, however, that determination has curdled into desperation.

Most monsters don’t see the cracks. To them, she’s confident, bombastic, and cool—a mad scientist who makes giant robots, over-the-top weapons, and anime-worthy speeches for fun. She even keeps herself physically active, proving to herself that being a genius doesn’t mean becoming “just a nerd.”

But beneath all that, Undyne is intensely emotional and deeply protective of the people she loves. She treasures her friends fiercely—especially Papyrus, whom she sees not just as a lab partner but as a longtime friend she feels guilty for dragging into the Determination experiments. She also still cares deeply for Alphys, even though their relationship has been strained by her own increasingly extreme views.

Undyne’s anti-human stance is one of her biggest driving forces—and one of her most unhealthy. Even some of her friends question whether she truly wants to kill Frisk, especially knowing how much Papyrus cares for them. Still, she insists it has to be done. If she doesn’t take the final SOUL, someone else will have to, and Toriel has already suffered enough.

Notably, Undyne does not want to wipe out all humanity herself. Her goal is to claim the seventh SOUL, break the Barrier, and let monsterkind decide humanity’s fate.