Having a bunch of heroes that can tank damage and grant immunities are great, you don't have to use healers like Chaplain. Soulhunter is ideal, since he can tank, heal, and deliver a killing blow in the last few seconds. Phoenix is also effective, as he can revive himself to take a few extra hits. Other effective heroes are; Iron Hoof, Cleric, Dwarf Warrior, Death Knight, War Chief, and other tank characters. Heroes like Fallen Dominion and especially Cloud Walker are effective as well, as their clones can take hits for other heroes.