Hive Leader

Let's discuss the reward for killing Nicholas instead.
I had an idea to create a second part of the dungeon, which would be guarded by Orcs, Necromancers, and Gnomes. The first ones will leave after collecting the Artifact set, the second ones after Nicholas's death, and you'll have to fight the third ones. But what's the point? I'd like to add something interesting, but I don't know what...