Lord Frieza incarnate in Gensokyo

A playboy weeb from our world, that doesn't know anything about Touhou, gets Frieza-sama powers and the appearance of Killua Zoldyck from Hunter X Hunter, then gets isekai-ed to Touhou Project world. In case you find incorrect information in the story, don't worry, it's not me who didn't know it, but the characters themselves, it's not like they have a wiki about their world like u