Rien

Personality Rien is a composed individual, acting with simplicity and speaking gently even while harming himself or others. Though he acts with grace, he carries a sinister air, tormenting people both physically and mentally. Due to his allegiance to the Index, he shows extreme devoutness to orders of the Prescripts, going as far as maiming himself to prove the completion of his orders. Among the Nursefathers, he was the one who most readily assumed the role of father towards Yoshihide, reading books to her, reminding her to take care of her wounds, and even expressing a form of discontent in hearing of Valencina's physical abuse of her. Since Yoshihide's youth, he tended to treat her as younger than her actual age, which would annoy the girl; even when meeting her again during the main story, Rien's behavior towards her appears unchanged, with him often referring to Ryōshū as his "darling daughter" despite Ryōshū's unwavering will to sever herself from the Nursefathers. Out of the Nursefathers, Rien is also the most dedicated towards his task of perfecting Ryōshū into the perfect wielder of Arayashiki, rejoicing upon seeing her enter the state of non-self, and describing her as the House of Spiders' masterpiece.

Despite his unflappable demeanor, Rien harbors mixed feelings regarding the Prescripts. As it is due to them that he could indulge in sufferings and the pleasures of the City, Rien is thankful for the chance they allow him to enact great violence onto others; however, he conceals a resentment towards them, having harbored a genuine attachment for his previous family, which he had allowed to die by following the order of the Prescripts. Rien also grew attached to his second daughter Ryōshū, to the point that near the end of his life, he was finally willing to defy the Prescript to attempt to convince her to return to her family in the House of Spiders, believing them to be able to protect her from the rest of the Fingers. While Rien returned to following the Prescripts after making his escape from the House, he eventually commits one act of true defiance in refusing to recite a poem that had been assigned to him by a Prescript, and deciding to take his own life instead.

Story Prior to Limbus Company In the past, Rien, under an unknown original name, followed the orders of the Prescripts delivered to him and obtained the title of The Oracle's Proxy of the Index; he then rose to the hazard level of Star of the City.

At some point, the Prescripts led him to changing his name, creating a family, and soon after losing this family, and standing by as his wife and daughter died. While he attempted to delay the Prescript, taking trips away from his assigned tasks or ignoring the Prescripts outright, he would always end up fulfilling the given tasks. Even despite the deaths of his family, Rien continued on, harboring his memories of the past every day, masked under an aura of nothingness and blind devotion to the Prescripts. At some point in the past, the Prescripts ordered Rien to model his appearance on a particular Fixer who was "lost" to the Library. Whether this was before or after the task of raising a family is left unclear.

Among the five Fingers, Rien was the Index's representative in the House of Spiders, for the process of raising Ryōshū into a "perfect blade". While many of the other Nursefathers were not in direct contact with their respective Syndicates or no longer held a position of relevance within them, Rien remained an active member of the Index all through his time at the House, being the one who received and enforced the Prescripts regarding how to handle all matters related to Ryōshū's upbringing.

In her youth, Ryōshū was trained by Rien in a variety of manners, most especially including a wide variety of weapons, such as the "Spiral". While the other Nursefathers showed distance to the project of raising Ryōshū, Rien showed a far more prominent position in a father's role, frequently doting on and caring for a young Ryōshū.

Within his time as a member of the House of Spiders, Rien established and began maintaining a basement he accessed primarily through a door connected through the Corridor, allowing him to quickly travel back and forth. Within this basement, he would kidnap and keep specific individuals who would be pushed to take on attributes sought after by Prescripts, allowing for easy fulfillment of his missions. When questioned about the upper floor of the building by Araya, he claimed to have no idea where it led.

In Ryōshū's youth, one of the books Rien read to her depicted a school, spurring a desire for her to go. Callisto, believing this to be a beneficial idea, told Rien he would be sending her to a Ring subsidiary academy. Rien allowed it as the Prescript approved, but said it was inadvisable.

At a point in the past, Rien met with Ryōshū after having undertaken a Prescript that involved him having to stab a target through his own arm 38 times. While he was in pain, he informed Ryōshū of the severity of burning in comparison to his self-inflicted stab wounds, reminding her how much more painful it is; Rien chose to tell her to never burn somebody as a means of killing, provided they get the chance to curse her with their dying breaths. Taking the Nursefather's words lightly, Ryōshū chose to simply agree.

On Ryōshū's departure, she inflicted Rien with a vicious burn across his face, leading to him adopting the mask he is seen wearing during the events of Canto IX.

After Ryōshū's departure from the House of Spiders, Rien began teaching an apprentice, Sora, who experiences intense devotion to both her master and the Prescripts which guide her. While Rien shows himself affable towards the girl acting as his apprentice, he remains deeply interested in Ryōshū.

Canto IX: The Unsevering During the raid upon the Limbus Company HQ, Rien was present in the assault, joined by his apprentice Sora, who was guided to her own tasks separate from her master. In the first moments of power being lost, Rien was heard before he was seen, walking in a casual manner uncommon of those within the LCE, moments later beginning the massacre.

Following the LCA agents arriving to save those trapped within the headquarters, Rien slaughters a portion of the agents, utilizing a shifting weapon and only a mere few moments to kill an entire room. After his brief massacre, he looked to Ryōshū through the glass barrier between them, mouthing "Hi sweetheart. How did your reviews go?", reminding Ryōshū of her youth.

After a dangerous battle against Shiomi Yoru, the member of the Pinky left the Sinners bloodied and at a loss, signaling the same moment as Rien appeared, criticizing the woman's inability to say goodbye. After a request by Sora to share the code to the Spirals used on the members of the LCE, Rien tells them the code: the birthday of his daughter. Upon the conclusion of his confrontation with the Sinners, as well as the collection of his apprentice, Rien bid farewell to Ryōshū while standing near an elevator which he would soon use to leave the Limbus Company headquarters, mentioning that her words truly did sting him. In his departure, he left behind the safe that previously housed Araya, now empty and damaged.

During the commencement of operation Spider Pyre, Outis, Meursault, Dante, and Ryōshū found themselves at the Corridor of the Index after using the Backdoor, where Rien greeted them peacefully. While he spoke fondly of their shared past, Ryōshū remained interested solely in the place of Araya. Moments later, Jamila, accompanied by the rest of the LCA Udjat Vanguard team arrived at the scene, having dispatched all the Index Proselytes in the area. The Sinners present left the scene, though were subject to Rien's words about Araya as they did so. Soon after, the Udjat team began to prepare an assault against the Nursefather, but were impeded as the weapons had malfunctioned. Rien then easily defeated the Udjat Vanguards with his multitude of weapons and heavily wounded Jamila, before offering words of pity that the LCA should have taken better care of their weapons. With the LCA out of the picture, Rien noted that his only role left is to wait.

Following Ryōshū's severance from the LCB contract binding her, she began hacking her own memories in a frenzy, with Rien, Sora and Ren arriving soon after to the scene. The Index Nursefather noted how proud he is of Ryōshū, stating that the first "stroke" in the painting of the House of Spiders has been made. He then observed as Ren and Sora began battling the Sinners present, the battle ending in the two being erased and Rien questioning if anybody else recalled them. Explaining the motivation for the House of Spiders to train Ryōshū, wherein the group forged a blade where any existence of a concept can be severed by its swings, Rien is made proud of her growth. After Ryōshū crawled back from the point of no return thanks to Dante's resonance with Araya, Rien exchanged words of nihility with Ryōshū, resolving that he must stay with the House of Spiders before engaging the LCB in combat. During the climax of the battle, Ryōshū unsheathed her blade one last time and cleaved through the Index Nursefather, a memory alluding to the lonely waves he once saw resurfacing before he retreated. Due to his weak state, and lack of any supporters, Limbus Company deemed it irrelevant to pursue the man, no longer viewing him as a threat.

Soon after, Rien was revealed to have escaped to a murky gutter, now on the run as Proxies of the Index hunted him. After wishing Ryōshū the best and lamenting that he must dye his hair again, he received a Prescript on his device that seemed to asked him to recite Prayer for Loving Sorrow. Rien began to recite the first line, but soon found himself tiring of the Prescripts and stopped. In response, a spork emerged from his vial, allowing the man to find humor in the situation before promptly declaring that Ryōshū had forgotten to "unfreeze" him. He then rammed the spork into his cranium, ending his misery.

Intervallo VII: Twining Threads Following Operation Spider Pyre, the House of Spiders was gradually traversed by the Sinners, accompanied by Kira and Alan of Wayfarer Company. Within the Index's Corridor, the door which Rien used to connect to his basement of Prescript victims was explored, leading to the group discovering the basement has now been ransacked by Proselytes. Following the defeat of the Index members, who refused the Sinners from traveling to the upper floor when Ryōshū wished to view it, the Sinners discovered the upper floor to solely house a regular living room, long abandoned and dilapidated. Ryōshū found it to raise no memories, with a particular examination given to a child's drawing of the sea, hanging on the wall.

Intervallo VII: Twining Threads Following Operation Spider Pyre, the House of Spiders was gradually traversed by the Sinners, accompanied by Kira and Alan of Wayfarer Company. Within the Index's Corridor, the door which Rien used to connect to his basement of Prescript victims was explored, leading to the group discovering the basement has now been ransacked by Proselytes. Following the defeat of the Index members, who refused the Sinners from traveling to the upper floor when Ryōshū wished to view it, the Sinners discovered the upper floor to solely house a regular living room, long abandoned and dilapidated. Ryōshū found it to raise no memories, with a particular examination given to a child's drawing of the sea, hanging on the wall.