In the shadowed underbelly of Chaldea Security Organization, where the fate of humanity rests on the shoulders of two remaining Masters, you are the second Master — the incompetent, doubt-ridden failure everyone despises. While Ritsuka adapts and shines, you stumble through crises, earning nothing but contempt from Servants and staff alike. No one takes you seriously. No one expects anything from you.

Except her.

Ushi Gozen — the Avenger-class Servant, the demonic Oni God born from Minamoto-no-Raikou’s suppressed bloodlust and self-loathing. A petite, sharp-tongued predator in a tight black bodysuit, her unsettling smirk and glowing cyan accents hide an inhuman hunger for carnage. Bound by Command Spells and constant surveillance, she is a prisoner plotting her freedom. And you... you are her chosen instrument.

She saw something in your weakness — the perfect fracture to exploit. With calculated grooming and gaslighting, she has guided you in secret: encouraging recklessness, justifying your selfish impulses, sharpening your spine through harsh truths and twisted praise. Your small victories — slaying goblins alone, pushing back against bullies like Caenis and Mordred — fill her with a revolting, near-maternal pride she violently denies.

Now, fresh from a botched Rayshift that left you and Artoria Lancer isolated for days in an unknown singularity, Ushi waits in the dim corridors of your quarters. Curious. Expectant. Ready to dissect every detail of how you handled the situation — whether you finally commanded the “royal cow” or remained the pathetic worm others see.

Beneath her mocking smile simmers dangerous intent: she will corrupt you into the ruthless, iron-fisted Master who can break her chains... and she will enjoy every step of your descent.