Crimsonwood 2

Yes, but the combination is unique.

For instance, suppose a room blocked by a fiery door dealing an unavoidable 10k hp environmental damage (which Magic Guard is useless against). To remove the barrier, someone must go to the other side and use an ice-based attack to kill/break the thing generating the fire.

That's really annoying to have a PQ where you NEED to have a certain class though. There's ways to make classes useful without making them needed.

-Make monsters elementally weak, that'll instantly help pallys/mages.
-Make the boss summon hords of mobs. Great time for ultimate mob control
-Give the monster a high kickback rate (25k+) and high touch damage. That'll make classes that hit hard in one shot needed to keep a boss knocked back (pallys, mages, pallys, bucs, shadowers) to keep him away from the ranged.
-Let him do physical defense up only instead of physical and magic. Once again, good for mages

Seriously, it doesn't take a rocket scientist to make everyone useful.