Zoltan/Siegebreaker: This one gave me the most trouble at first, now it's easier than Ghom/Rakanoth. Go after Zoltan first, in fact, stay away from Siegebreaker. If he goes after you, run to one end or the other. He'll come ahead of Zoltan, your dogs and garg will go after him, and he'll spend all his time messing with them. Run around him, find Zoltan. Stay out of his tornadoes. If you get caught in his slow time bubble, get out of it. You can burn a Spirit Walk to do that at full speed. Once you're in range, plague him until he runs off. You can chase him with Spirit Walk, too. Keep plague bats up on him as long as you can, then run off to the other end. If Siegebreaker comes after you, take off. If Zombie Dogs are dying, blow them up and bring them back. Rinse and repeat until Zoltan is gone. Wait for his stuff to go away if you need to, then start moving in on Siegebreaker from the side. Plague him as long as he isn't paying attention to you. Rinse and repeat again. [Edit: next time I tried blowing up the dogs on Siegebreaker, I got one-shotted every time by his reflect damage capability. Probably because my DPS had about doubled and my life had stayed the same. Anyway, I just kept tanking him with the dogs and the garg, pinging him with firebombs until life got low, kiting, taking health potions, and so on.]