Merveil pretty much destroyed me

Dont forget you can ask for help in global chat, many poe players are the friendly sort (in my experience). Or you can create/find a party to deal with the common enemy :P

That said, heres a few tips that works for fighting any boss:
* DoT (such as firetrap or firestorm) are great since it suppresses their energy shield regeneration.
* Spammable minions (skellys, raging spirits, totems etc) are great to keep the aggro off you.
* Cast a tp when you enter the boss lair; if you run into trouble / out of charges, you have a easy out/refresh.