Merveil completely decimated me on my Witch.
I face tanked her on my super marauder, but how do I do it as a non-tank? I have a lot of tanky witch things (ES).
Lots of moving around and a really long period of time to pull it off. Either that or you'll have to find a tank to help you. I found it rather difficult to do the first part of merveil as a non-tank, dropping a TP at the entrance to her area helps a bit, but unless you have some way of dodging her spells you're pretty much screwed. I managed to kite her through a bunch of my traps around that wall near the entrance. But that took FOREVER, waiting for mana regen and trap regen and health regen when I screwed up and got hit. Her second form was really easy though.