Cataclysm: Good Design I

So what about the good design.

Special Mechanic to Clear Trash in Dungeons
Very brilliant idea and implementation, such as NPC who shows up to clear out the trash for players, dragons from Grim Batol which are controlled by players to blast the mobs on the way to first/second boss etc.

Possible Improvements: To implement mini-games to reduce the dungeon trash on the run.