Demon slayer

Intro also, the voice is your voice in the thing i know. im not fun at all sometimes. Anyway, your brother is Douma, and you're the girl in the picture. The story: You and Douma were playing, then you went too far and fell into the infinity castle, and Douma also went into the infinity castle *of cores* and you met all the upper moons,sorry if i missed alot of them...