The Difficulty Has Not Increased In Casual Content.

[Deceptus]

The Mist Dragon is the only boss I know of in the game that is certain guaranteed death, or all but if the healer gets hit with the AoE.

It does 60% or more of a healer's health in damage at ~350-355 iLevel, and it stuns them for 5-6 seconds, and it puts a DoT that does ~15% health per tick. 3 ticks is death if they did not have a HoT on them at the time.

BLM too. Erase has a use!