Anime Like Fate/kaleid liner Prisma☆Illya: Vow in the Snow
Shirou builds a life where Miyu is just his sister, not a weapon. The Ainsworth family burns that down in one afternoon. What hits is watching him realize that loving her and keeping her safe were never the same thing, and that some people will always be hunted no matter how normal you try to make their life.
SYNOPSIS
Shirou has built a quiet life with Miyu, a girl pulled from the wreckage of a destroyed city. Everyone warns him she's dangerous, that her power makes her a weapon first and a person second. But he refuses to see her that way. He treats her like family, like a sister who deserves a normal childhood. That peace shatters when the Ainsworth family makes their move. They take Miyu, planning to use her in a ritual sacrifice that will harness her immense abilities for themselves. Shirou realizes too late that his attempt to give her an ordinary life made her vulnerable. Now he faces an impossible choice. Rescuing Miyu is only half the battle. The real question haunts him: what do you do when someone you love is also a catastrophic force of nature? Her potential for good is matched only by her capacity for destruction. Saving her from her captors won't solve the larger problem of what she represents and what she might become.
