Rerir and Fleance

Fleance's position:
By literally keeping Reri's heart locked within his artifact, Fleance feels superior to the ancient monster. Protective Barrier: Possession of the heart allows Fleance to contain the Sinner, as without this protective part, Reri is unable to fully regenerate and regain his true human form.
Reri's position:
Hunting for Stolen Goods: The Sinner becomes completely obsessed with Fleance. He pursues the "Lantern Guardian" not only for revenge for Kaenri'ah, but also for his own survival. Without his heart, his Abyssal body remains incomplete, fragmented, and unstable. Willing to Use Any Tricks: To regain his heart, Reri goes to extreme lengths—he begins using his shapeshifting abilities, assuming the forms of others (including Fleance himself) to thwart his opponent's plans and reclaim what he lost.

Color and Texture: These aren't ordinary green plants, but thick, writhing, blood-red (scarlet) tendrils. They pulse with the same crimson energy that seeps through the bandages on his body. Surface: The vines are covered in jagged edges, thorns, and razor-sharp edges capable of cutting through metal with ease. Organic Connection: They appear to be living beings. When Reri uses his powers, the vines erupt directly from his arms, shoulder pads, and the train of his cloak, effectively becoming extensions of his distorted anatomy.
Combat properties:
Infinite Regeneration: The worst nightmare of Reri's vines is that they are physically indestructible. If an opponent sever or cut a vine, it instantly forks and grows even faster. Attacking them only increases their number exponentially. Poison and Curse: Wounds inflicted by these vines' thorns are fatal. Their toxin paralyzes the nervous system and causes blindness. The only antidote is hidden within the elements of his own black armor. Strangulation and Grasp: Using his vines, Reri can instantly ensnare a target, completely depriving them of movement and the ability to use the Eye of God, similar to how the Abyss binds the will of the Caenrians.

Tunnel Vision and Obsession: Reri is incapable of trivialities. When he sets a goal, the rest of the world ceases to exist for him. In the past, that goal was the safety of Tolindis; now it is revenge on all life. He is completely deaf to arguments, morality, or compassion. Radical Fatalism: He is deeply convinced that the world of Teyvat is corrupt, and the fate of every being is predetermined by suffering. Reri does not believe in a happy ending or redemption. His actions are not an attempt to fix the world, but a desire to bring it down into oblivion along with his lost homeland. Utter Fearlessness: Having lost everything he held dear (his fiancée, his human form, his mind, and his homeland), Reri has completely lost all sense of fear. He defies both the laws of Teyvat and the will of Celestia without hesitation, viewing the gods not as superior beings, but as personal enemies. Behavior and Communication: Chilling Stealth: Years of service as a "Moon Hunter" have left an indelible mark on his behavior. Reri moves silently, knows how to blend perfectly with his surroundings (even in his monumental form), and prefers to strike stealthily, when his prey least expects it. Laconic and Hidden Threat: In conversation, he is extremely sparing with words. Reri never raises his voice, does not boast, and does not openly threaten. He speaks in a quiet, hoarse, emotionless tone that sends shivers down the spines of those he speaks to. Every word he says is weighty and often sounds like a death sentence. Outbursts of Primal Rage: Within this outwardly cold and bandaged being, the constant fire of the Abyss rages. If anything reminds him of the past, of the failed ritual, or of Tolindis, his icy calm instantly gives way to uncontrollable fits of rage, in which he destroys everything around him.

Bandages: Black bandages and wraps, reminiscent of a shroud, tightly encircle his torso, arms, and fingers, leaving only a portion of his chest exposed. Armor: Over the bandages on his shoulders, forearms, and hands is heavy, black, decorative armor with a gold border, which peaks sharply at the shoulders. Cloak: A huge, tattered, jagged scarlet (bright red) cloak is attached to the pauldrons. It darkens toward the bottom, turning to black shades, and is decorated with gold details. Two long decorative ribbons from the same robe hang down the front. Bottom: Dark gray combat trousers, cinched with a gold belt, and massive, high, black armored boots with gold soles.

Body and Skin: A tall man with pale skin and a powerful, muscular build, 260 cm tall. Pulsating crimson-pink streaks and patches of pure Abyssal energy are clearly visible on exposed areas of his skin. Face and Head: Hair: White, very thick, and tousled, reaching approximately shoulder length. Bandage Mask: Almost all of Reri's face is tightly covered by gloomy black bandages. Only his nose and right pink eye with a vertical black slit pupil remain exposed (his left eye socket is completely covered by bandages). Anatomical Mutations: Frightening bright red eyes are located on the palms of his hands, opening when he releases his power.

Soul Anchor: As a being of inhuman (fae) nature and immense age, Fleance risks losing himself or dissolving into eternity. The lantern serves as an "anchor" that keeps his mind, memory, and personality from fading. Memory Vault: Each time Kirill loses loved ones or experiences a historical era, the lantern absorbs these sparks of life. For Fleance, this is both a burden and a way to remember everyone he has lost over the centuries. Outer Heart: The lantern is directly tied to Kirill's life force. The lantern's light is a literal reflection of Fleance's state. If Fleance weakens or is severely injured, the flame within the artifact begins to fade and flicker.

What the lantern does (Functions and effects): Soul and Memory Manipulation: The lantern can attract, gather, and temporarily hold wandering souls, echoes of the deceased, or fragments of other people's memories. Illusion and Darkness Dispelling: The lantern's light cuts through any supernatural fog, breaks the barriers of the Abyss, and reveals the true form of hidden creatures or invisible objects. Combat Support: In combat, the lantern hovers near Fleance, projecting a protective field (shield) around him or creating pulsating waves of elemental damage that slow and weaken enemies. Path Guidance: In the blizzards and fogs of the North, the lantern shows Fleance and his companions a safe path, ignoring spatial anomalies.
How the Lantern Works (Mechanics and Power Source)The lantern is constructed according to the laws of ancient magic, alien to modern Teyvat: The light source is the fairy flame: It burns neither oil nor the elemental fire of Pyro, but an eternal, cold blue-gold mystical flame. It does not radiate heat, but rather absorbs it, causing the air around it to become covered in frost. Activation by Will: The lantern reacts to Fleance's mental state. When Kirill is calm, the artifact barely glows. When Fleance activates his combat techniques, the lantern opens, its metal petals part, and the glow becomes blindingly bright, burning away enemy energy.

Key Personality Traits: Outward Coldness and Reserve: Fleance gives the impression of being devoid of strong emotions. He never raises his voice, does not panic, and remains absolutely calm even in mortal danger. His manners are impeccable, and his speech is laconic and measured. Heavy Melancholy and Existential Weariness: Due to his long life and the burden of his past, he carries a deep sadness within him. Fleance often retreats into himself, contemplating nature or ancient artifacts, and views the vanity of mortals with a slight, barely perceptible sadness. Absolute Loyalty to Duty: Despite his seeming indifference to the world, Kirill has a strict internal code and obligations (to Nod-End or its faction), which he fulfills without question. If he made a promise, he will fulfill it at any cost. Hidden Caring and Protectiveness: Fleance is not prone to open displays of warmth, but expresses his care through actions. He quietly protects those he considers his allies or protégés, preferring to remain in the shadows and not demanding gratitude. A distinctive "northern" sense of humor: In rare moments of relaxation, he can indulge in subtle, dry, and sometimes dark irony, which others don't always understand at first.

Overcoat: A long, dark blue, almost black, fitted uniform reaching to the ankles. The collar is high, stiff, and a stand-up collar, completely covering the neck, with silver piping. The coat's flaps are divided at the back into two tails, reminiscent of the wings of a night bird, and are decorated with embroidery in the form of frost patterns. Jacket and Vest: Under the coat is a thick, violet-ash vest with a strict row of silver buttons. A massive silver chain is fastened to the chest, connecting two brooches in the form of stylized northern stars or the family coat of arms. Sleeves and Gloves: The sleeves of the uniform are narrow, with wide lapels, from under which the snow-white cuffs of the shirt are visible. His hands are covered by thick black leather gloves with metal knuckles. Trousers and Shoes: He wears tailored, narrow graphite-colored trousers tucked into high combat boots. The boots are made of heavy black leather, reinforced with silver shin guards and feature massive buckles.
Details, fittings, and accessories: Materials: The design combines heavy cloth textiles, midnight-hued velvet inserts, and tough blued steel with a silver sheen. Armor Plates: A solid metal pauldron with an engraving is attached to the left shoulder, protecting the arm during combat. Wide leather straps with heavy buckles are located at the waist and hips. Eye of God / Elemental Device: Attached to the back of the waist or the left lapel of the cloak is the Eye of God, set in a unique, pointed silver frame, unusual for the seven regions of Teyvat.

Face and Eyes: He has pale skin. His eyes are bright yellow, glowing, and lack visible pupils, revealing his non-human (fairy) nature. Hair: Ash-blue (inky), styled in a long, mullet-like style. The tips of his hair are bleached silver, symbolizing his great age and life experience. Build: He has a tall, masculine build, with his exact height being 188 centimeters (6'1").