This is what i think.Finn is already gone,but he will continue with this show in another role.Maybe Finn Collins have ancestry parentage people who live on earth before the nuclear war and one or many of the descendants lives along with the grounders people (other clans) or live in the city of lights.This is only a theory but if the actor wants to continue with this show certainly will find a way.Finn character had to die because it was right.Blood demands blood as crime requires punishment. Though many fans find it difficult to accept,finn's death was the only solution for things to go forward. Happy holidays to all !!!
Review of Spacewalker
Finn is dead but i think the actor plays another role in this TV show.
25 December 2014
Warning: Spoilers