Duriel was HARD. at first i tried to lifetap him and have my merc tank him but either he would turn on me and i would teleport away, or he would own my merc. then i tried shooting him with my bow and teleporting around but that was hopeless. So i went back to my initial strategy and this time when he knocked my merc away and turned on me i tanked him very easily actually. SO i was able to slowly whittle his health away.
whenever there are many fire immunes, such as in tal rasha tomb there no hope in me killing them. I would need a dream for that. so if i dont get any better gear soon i am considering putting points into orb and CM to deal with fire immunes, however i will still mainly be chant. I dont see any other way to clear P8 chaos sanc. unlesss i find some really nice stuff.... fast