The Fallen Hero Of Ooo

This is a story, a story about Finn the human. As we all know Finn has gone through a lot of shit. But there are things we don't even know about him. Do you ever wonder what it was like before the bombs, how the Lich came to being, why Finn was the only human left? Many of these questions will be answered, but that will only let more arise. This story takes place 5 years after the comet with Finn grown up but a nearly broken man. His friends having secrets that seem suspicious. These friends will become Finn's enemy... or is it the other way around? Well enough chit-chat out of me, let's get into the story shall we?
(And just to let you know there will be violence, swearing, and alot of smut.)