fate/first order derivative

An eccentric nerd finds himself stuck in a time loop after something weird happens down the street at Shirou Emiya's place. Tom Tomonaga doesn't know why he's repeating the same two weeks over and over again. He doesn't know anything about magic, the secret world of mages, or the Grail War. But he'll have to learn if he wants to escape back into a world that makes sense, all while arguing with a pushy voice inside of his own head and discovering how many ways there are to die (spoiler: they all suck.) Also features science in an absurd universe, frequent psychological trauma, and -- oh yeah -- the end of the world.

Rated Mature/16+ for profanity. Reader discretion is advised.