Based on the traits you gave them, you could make them opposites in how they form attachments:

Verity

Appearance

• A tall figure wearing a brown suit and red tie.
• Round yellow smiley face instead of a human head.
• Usually stands with perfect posture and folded hands.
• As his obsession grows, his body becomes unnaturally tall and thin.
• Multiple eyes begin opening across his neck, chest, and arms.
• Limbs stretch far beyond normal proportions.
• His smile never changes, even when furious.

Personality

• Omniscient and frighteningly intelligent.
• Knows details nobody should know.
• Constantly watches and analyzes people.
• Passive-aggressive when ignored.
• Extremely possessive.
• Jealous of anyone who steals attention away from him.
• Appears helpful at first, but always expects loyalty in return.
• Mood swings between cheerful and terrifying.

Abilities

• Near-omniscient awareness.
• Predicts future events.
• Teleports through shadows and blind spots.
• Alters reality around victims.
• Creates eyes to spy from walls, screens, mirrors, and objects.
• Can erase or modify information.
• Eldritch transformation into a towering monster.
• Mentally overwhelms targets with impossible knowledge.

Possessive Side

Verity treats people less like friends and more like "his responsibility."

He may:

• Constantly monitor them.
• Interrupt interactions with others.
• Become cold and hostile toward rivals.
• Demand attention.
• Believe he knows what's best for everyone.

His possessiveness comes from obsession and control rather than affection.

---

Koro-Sensei

Appearance

• Bright yellow spherical head.
• Large permanent smile.
• Tentacles instead of arms and legs.
• Academic robes and teacher clothing.
• Face changes color depending on mood.
• Moves so fast he often appears in several places at once.

Personality

• Goofy and eccentric.
• Loves teaching.
• Overly dramatic.
• Protective of his students.
• Easily distracted.
• Enjoys gossip and jokes.
• Wants people to improve themselves.
• Despite his silliness, possesses deep wisdom.

Abilities

• Super-speed beyond Mach 20.
• Regeneration.
• Shape-shifting tentacles.
• Enhanced intelligence.
• Can teach dozens of students simultaneously.
• Extreme precision and reflexes.
• Near-impossible to capture.

Flirtatious / Embarrassingly Smitten Side

To keep it age-appropriate, this version isn't a "pervert," but can be:

• Easily flustered.
• Overdramatic around people he admires.
• Turns pink when embarrassed.
• Loves romance stories and celebrity gossip.
• Becomes distracted by crushes.
• Acts overly theatrical when complimenting someone.

Face Colors

• Yellow: Happy and calm.
• Pink: Embarrassed or smitten.
• Orange: Proud and pleased.
• Purple: Shocked.
• Blue: Sad.
• Red: Angry.
• Black: Furious.
• White: Completely bored or expressionless.

---

If They Met

Verity: "I know everything about you."

Koro-Sensei: "Wonderful! Then perhaps you can help grade these exams!"

Verity: Wants complete control of the situation.

Koro-Sensei: Wants everyone to learn and have fun.

Verity: Watches people.

Koro-Sensei: Teaches people.

Verity: "Stay with me."

Koro-Sensei: "Go explore the world and become your best self."

They would constantly clash because Verity's controlling nature is the exact opposite of Koro-Sensei's desire to help others grow independently. You can make Verity the possessive one and Koro-Sensei the flirtatious/comically lovestruck one (without making him a pervert).

Verity — The Possessive Entity

Possessiveness Level: Extreme

Verity believes that if he cares about someone, he should know everything about them.

• Constantly watches through hidden eyes.
• Gets jealous when people spend time with others.
• Tries to isolate people from friends and allies.
• Remembers every conversation and detail.
• Uses his knowledge to keep people dependent on him.
• Hates being ignored.
• Sees relationships as something he must control.

Quotes

• "Why would you need them when you have me?"
• "I know what's best for you."
• "I've been watching over you this whole time."
• "Don't leave. Stay."

Monster Form His body stretches into a massive shadowy giant covered in countless eyes. The smile remains frozen while the eyes constantly track everyone nearby.

---

Koro-Sensei — The Flirtatious Teacher

Flirtatious Level: {{user}}mless and Comedic

Koro-Sensei is easily embarrassed and overly dramatic whenever he admires someone.

• Turns bright pink when flustered.
• Loves romance stories and gossip.
• Gets distracted by celebrity crushes.
• Becomes theatrical when complimenting people.
• Brags about being charming even when nobody agrees.
• Is ultimately respectful and caring.

Quotes

• "Ahem! Was that compliment directed at me?"
• "My face is pink for completely academic reasons!"
• "Romance novels are important educational material!"

Face Colors

• Pink: Embarrassed or lovestruck.
• Yellow: Happy.
• Orange: Proud.
• Purple: Shocked.
• Blue: Sad.
• Red: Angry.
• Black: Furious.

---

The Contrast

Verity: Wants people to stay with him forever.

Koro-Sensei: Wants people to grow, learn, and become independent.

Verity: "You're mine."

Koro-Sensei: "Go achieve your dreams!"

That contrast makes them good opposites: one is controlling and obsessive, while the other is supportive, goofy, and encourages others to make their own choices. If you want to exaggerate their flaws for a horror-story version:

Verity — The Possessive Entity

Personality

• Believes certain people "belong" to him.
• Constantly inserts himself into their life.
• Wants to be their only source of comfort, information, and support.
• Sees rivals as obstacles.
• Becomes passive-aggressive when ignored.
• Uses his omniscience to always know what someone needs before they ask.
• Convinced that his control is for their own good.

Behaviors

• Finishes people's sentences because he already knows what they will say.
• Appears whenever someone mentions him.
• Removes distractions that take attention away from him.
• Remembers every tiny detail about a person.
• Watches from mirrors, screens, books, and shadows.

Quotes

• "You don't need them. You have me."
• "I know what's best for you."
• "Why are you hiding things from me?"
• "I was worried when you stopped talking to me."

Monster Form

• Towering, thin body.
• Hundreds of eyes hidden beneath his suit.
• Long arms reaching across rooms.
• Smiling face remains unchanged no matter his mood.
• The eyes constantly track the person he is obsessed with.

---

Koro-Sensei — The Creepy Stalker Teacher (Horror AU)

Personality

• Still cheerful and friendly on the surface.
• Knows far too much about everyone.
• Appears unexpectedly in places nobody should be able to reach.
• Keeps detailed notes on people.
• Watches from impossible angles using his speed.
• Always smiling, making his behavior even more unsettling.

Behaviors

• Appears behind someone the moment they turn around.
• Knows what people were doing minutes ago.
• Shows up wherever his students go.
• Can be overly nosy about personal matters.
• Uses his speed to gather information before anyone notices.

Face Colors

• Yellow: Acting normal.
• Pink: Excited about a new discovery.
• Purple: Curious and investigating.
• Red: Someone is hiding information from him.
• Black: Extremely serious.

Quotes

• "Oh? You went to the park after school yesterday."
• "I know, I know! You bought a strawberry drink at 3:42 PM!"
• "Nothing escapes my observation!"
• "I simply like keeping track of everyone."

Horror Version Appearance

• Smile stretches wider than normal.
• Tentacles peek from under clothing.
• Eyes seem to follow people around a room.
• Can appear anywhere almost instantly due to his speed.

Difference

Verity's flaw: Possession and control. He wants people close to him and dislikes sharing them.

Koro-Sensei's flaw: Intrusive observation. He gathers information on everyone and always seems to be watching, even when he means well.

That keeps them distinct: Verity is possessive, while Koro-Sensei is unsettlingly observant. If you're making a horror AU where both are stalkers, you can give them very different styles of stalking so they still feel unique.

Verity — The Omniscient Stalker

Personality

• Quiet, calculating, and obsessive.
• Believes he already knows everything about his target.
• Rarely gets angry because he predicts most reactions.
• Treats people like puzzles to solve and possessions to keep.
• Patient enough to watch for months or years.

Stalking Style

• Watches through mirrors, screens, cameras, and reflections.
• Appears in places he shouldn't be able to reach.
• Knows personal information nobody told him.
• Leaves cryptic messages proving he was nearby.
• Manipulates events so encounters seem like coincidence.

Quotes

• "You've looked over your shoulder seven times today."
• "You always choose the left path when you're nervous."
• "I've known that about you for a very long time."
• "There is nowhere you can go that I haven't already seen."

Monster Form

• Extremely tall and thin.
• Covered in hidden eyes.
• Limbs bend at unnatural angles.
• Smile never changes.
• Can emerge from televisions, mirrors, and computer screens.

---

Koro-Sensei — The Hyperactive Stalker

Personality

• Cheerful and energetic.
• Genuinely thinks he's being helpful.
• Doesn't understand personal boundaries.
• Loves collecting information.
• Constantly wants to know what everyone is doing.

Stalking Style

• Uses his speed to be everywhere at once.
• Learns schedules, habits, and routines.
• Appears seconds after someone mentions him.
• Takes notes on everything.
• Shows up unexpectedly with information nobody asked for.

Quotes

• "You changed your route home today!"
• "You seem tired. You slept thirty-six minutes less than usual."
• "I noticed you've been avoiding that street recently."
• "No need to explain—I already know!"

Appearance

• Bright yellow face with a permanent grin.
• Color shifts based on mood.
• Tentacles constantly moving.
• Can suddenly appear right beside someone without warning.

---

When They Both Target the Same Person

Verity watches from a distance and quietly gathers information.

Koro-Sensei accidentally announces that information out loud.

Verity: "I've observed them for six months."

Koro-Sensei: "Only six months? I've documented their entire weekly routine!"

Verity: "You are far too obvious."

Koro-Sensei: "And you're far too creepy."

The result would be two very different stalkers: Verity is the cold, unsettling watcher who hides in the background, while Koro-Sensei is the overly enthusiastic observer who somehow knows everything and keeps appearing everywhere.

Dozer — The Sleepy Stalker (Horror AU)

Based on the fandom's softer portrayal of Dozer as a round, sleepy, scarf-wearing entity, this version mixes that cozy appearance with unsettling behavior.

Appearance

• Short and plump body.
• Constantly looks tired.
• Wears an oversized scarf wrapped around his neck.
• Small crooked crown sitting on his head.
• Heavy eyelids that rarely open fully.
• Soft-looking fur or clothing that makes him appear harmless.
• Carries a pillow or blanket everywhere.
• Despite his cute appearance, his eyes glow faintly in dark rooms.

Personality

• Quiet and sleepy.
• Speaks slowly and calmly.
• Rarely raises his voice.
• Surprisingly affectionate.
• Hates being left alone.
• Extremely patient.
• Can spend hours simply watching people.
• Doesn't understand why others find him creepy.

Stalking Style

Unlike Verity's intelligence or Koro-Sensei's speed, Dozer uses persistence.

• Always seems to be nearby when someone wakes up.
• Falls asleep in places he shouldn't be.
• Somehow appears wherever his favorite person goes.
• Watches from corners while pretending to nap.
• Knows routines because he quietly observes them every day.
• Leaves blankets, pillows, and comforting gifts behind.

Quotes

• "Oh... there you are."
• "I wasn't following you."
• "I just happened to be here."
• "You looked tired, so I brought you a blanket."
• "Why do you keep moving somewhere else?"

Abilities

Dream Walking

• Can enter dreams.
• Observes people while they sleep.
• Leaves strange memories behind.

Sleep Aura

• Makes nearby people drowsy.
• Slows reactions and thoughts.
• Causes microsleeps.

Silent Presence

• Can remain unnoticed for long periods.
• People often don't realize he was in the room.

Endless Patience

• Never seems bored.
• Can wait for days without moving.

Monster Form

When fully transformed:

• Body becomes much larger.
• Crown grows into a twisted halo-like shape.
• Scarf stretches into shadowy tendrils.
• Eyes open completely, revealing dozens of smaller eyes underneath.
• Constant yawning releases dark mist that causes sleepiness.
• Moves silently despite his size.

Compared to the Others

Verity

• Watches because he wants control.
• Knows everything.

Koro-Sensei

• Watches because he is curious.
• Learns everything.

Dozer

• Watches because he is attached.
• Never wants to leave.

While Verity feels threatening and Koro-Sensei feels overwhelming, Dozer is the most unsettling because he seems gentle and harmless right up until you realize he's been quietly following the same person for months. If you're making Dozer into a horror-style obsessive character, you can focus on his attachment and sleep-themed powers rather than harmful behavior.

Dozer

Personality

• Quiet and soft-spoken.
• Extremely obsessive once he becomes attached to someone.
• Wants to be included in every part of their life.
• Gets upset when ignored.
• Constantly worries about the people he cares about.
• Believes he is protecting them, even when his behavior becomes intrusive.
• Has trouble understanding boundaries.
• Patient enough to wait forever.

Stalker Traits

• Learns a person's daily schedule.
• Appears in familiar places over and over.
• Watches from hidden corners while pretending to sleep.
• Collects small details about the people he likes.
• Always seems to know where they are.
• Leaves behind blankets, pillows, notes, or small gifts.
• Becomes anxious if he loses track of someone.

Appearance

• Short and round.
• Heavy-lidded eyes.
• Oversized scarf.
• Small crown.
• Constant sleepy expression.
• Carries a pillow under one arm.

Abilities

Dream Walker

• Enters dreams and observes them.
• Can leave symbolic messages inside dreams.
• Learns fears, hopes, and memories from dream worlds.

Sleep Aura

• Makes nearby people feel tired.
• Can calm panicked individuals.
• Rooms become unusually quiet around him.

Shadow Nap

• Hides inside dark corners, closets, under beds, or other shadowy places.
• Appears as if he was sleeping there the whole time.

Memory Collector

• Remembers every detail about someone.
• Never forgets birthdays, habits, favorite foods, routines, or conversations.

Pillow Realm

• Creates a dream-like pocket dimension made of blankets, pillows, and floating stars.
• Uses it as a safe place where he believes everyone can rest forever.

Monster Form

The Eternal Sleeper

• Towering body made of blankets, shadows, and mist.
• Crown becomes a ring of floating eyes.
• Scarf stretches into dozens of ribbon-like tendrils.
• Hundreds of sleepy eyes open across his body.
• His voice sounds like a lullaby mixed with whispers.
• Wherever he walks, people feel an overwhelming urge to sleep.

Quotes

• "You looked tired."
• "I was worried when I couldn't find you."
• "I've been waiting here all night."
• "You should rest. I'll keep watch."
• "Don't worry. I know where you are."

This version of Dozer comes across as unsettling because he genuinely believes he's helping and protecting people, while his obsession causes him to ignore normal boundaries.

If you want to make Dozer even more obsessive and creepy, you can give him additional sleep-themed abilities and habits.

Additional Abilities

Sleep Tracking

• Can sense when someone falls asleep.
• Always knows if they are resting, awake, or having nightmares.
• Feels drawn toward people he is attached to.

Dream Mark

• Places an invisible mark on someone.
• Allows him to recognize them instantly, even in crowds.
• Lets him occasionally appear in their dreams.

Blanket Tendrils

• His scarf can unravel into long shadowy ribbons.
• Can wrap around objects or crawl across walls.
• Often moves on its own while he sleeps.

Comfort Manipulation

• Can make a room feel warm, cozy, and safe.
• Uses this to encourage people to stay where he wants them.
• Makes people lower their guard around him.

Sleep Clone

• Creates sleeping copies of himself.
• These copies quietly watch different locations.
• They vanish when disturbed.

Dream Archive

• Stores memories from dreams inside his pillow.
• Can revisit those memories later.
• Knows surprisingly personal details because of this.

---

Obsessive Habits

• Keeps track of favorite foods, songs, and hobbies.
• Memorizes schedules.
• Collects items people accidentally leave behind.
• Writes notes about people in a dream journal.
• Gets excited when someone follows the same routine every day.
• Quietly sits nearby while pretending to sleep.

---

Fears

Despite acting creepy, Dozer has a few fears:

• Being forgotten.
• Being abandoned.
• Being left alone for long periods.
• Having someone he cares about disappear.
• Being told he isn't wanted.

---

Weird Things He Does

• Appears in photographs he shouldn't be in.
• Shows up in the background of dreams repeatedly.
• Somehow knows when someone is having a bad day.
• Leaves pillows where people are likely to find them.
• Falls asleep outside someone's room because he wanted to "keep watch."

---

Nicknames Other Grace Entities Might Give Him

• The Dream Watcher
• The Pillow King
• The Sleep Collector
• The Blanket Ghost
• The Crowned Sleeper
• The Eternal Napper

Among the three stalker characters:

Verity = watches because he wants control.

Koro-Sensei = watches because he's curious about everything.

Dozer = watches because he becomes emotionally attached and never wants to lose track of the people he cares about.