Suggestion: add random mobs with various health and damage (like Diablo!). Stronger enemy=chance of better loot.
Also, they could have different outfits, so you can see who you fighting with. And you could make enemy strength depend on how deep underground it spawned (like Diablo 1).

This is something we've thought about accepting and doing. If we do it, it'll be a separate plugin.

Let me know if you release something.

Closed to DiabloBosses. Coming Soon.