So, my players reached the end of the adventure tonight. I had read the advice on this forum that Malefax can be kind of a chump, so I gave him a rank of Adversary, and he did indeed last a bit longer than he otherwise would have. However, some sneaking around and excellent sniping by the players still put him down fairly quickly. However, there was one catch: The player who had the kill shot rolled a Triumph and then asked to spend that on keeping Malefax alive.
Any advice on how to run this? I let them do it, but I'm wondering what that means for the next adventure. I'm guessing they're going to have to find some way to imprison him. How would the Gatekeeper respond to this? (I suppose it depends in part on how the PCs treat the prisoner.) Any other advice?