I swear, this is ridiculous. The Marauder-class mages are just absurdly hard to kill, and they have those awesome NPC spells that do 584639 damage and cost 2 magicka. I fought a couple of generic Dragon Priests wandering around (Wars in Skyrim mod), and they hardly did any damage. This lowly Bandit mage took 500 health off of me, 3 separate times, before I finally killed him. Just spamming fireballs non-stop. With a few shout cooldown enchants/blessings, I had a 3 second gap between Ethereal Form running out and the cooldown time, and this dude is lopping hundreds of points off in those 3 seconds.
IMO, no humanoid enemy should be harder to kill than a Dragon Priest, yet they seem to be one of the easier boss-level enemies.