If I were putting money down on it my bet is this... Burt does not get to kill Scratch, but he does get to sacrifice himself to ensure her elimination. I think Burt is still going to come out like a hero. Like the soldier who jumps on a grenade to save his unit, Burt is going to do something that gets himself killed but will save the others and give Riley the opening she needs to take Scratch out with an arrow to the dome or something. Riley makes the kill but it never would be possible without Burt. That is my guess anyway.