<"Spoilers!"> is a Human who got sucked into Equestria via magical device built by Twilight from Renascence-era plans, who may or may not fall into a multiverse of alternative selves down the line as the story progresses.

Story is initially set to take place before Season 4's Finale, so no blown-up Library or such… yet. Maybe.
Currently writing is being done in bursts when they can be channeled, so don't be surprised if there's cliffhanger chapter endings.