The dungeon is really annoying.
many mobs are stacked together so a simple mistake can wipe your group, which then leads to a very miserable run through the dungeon to reach the boss.
i suggest that some kind of an unlockable teleport is added to it.
with each boss you unlock a check point u can teleport to.
it can be a simple flightmaster that can send you to each floor.
or maybe an elevator.
shorten the run time cause it wastes a lot of time for no reason.