Reincarnated

Hi im Miya, i got reincarnated as soon as i died earlier by an accident and heard a weird voice after i died. "Welcome back Master" those words were stuck in my head thinking that someone would called me master nor why am i alive from now on, i was summoned in a place that I'd never expect to. Someone saw me lying in the floor thinking that i was weird, Miya: Where am i?, Unknown: such a powerful one, we should take care of this one we couldn't handle it if we attack right now, we're lucky to see someone powerful as this to be lying in the floor looking like an falling angel. Miya's thoughts : Who are they? why are they taking me in a basement full of books? Are they a historians? I hope they wont kill me...