Deep in the caves to the northwest, a certain psychic-slash-scientist explores, black dagger in his right hand. His left is raised, and constantly flares with a reddish aura, resulting in a glow that he uses to help light the way here.
He hardly believed what he'd heard of this place, of course. People being resurrected randomly, gaining gifts based on what they'd killed? Even for the Nexus, that was new to him, and it struck him with an idea.
If such creatures could have weapons and armor made from them in that sense, better than mundane ones, it's possible that such weapons could be made from the monsters themselves. Such would require obtaining materials from them, of course.
And so he came here.
Ah, what I do for science.