Does anyone have tips for beating the lich in the newer survival level? My friends and I have tried many three and four player games and don't have much trouble leading up to the boss, but we've found it impossible to defeat him without crutches. He has a base of 20000hp (which seems to be multiplied depending on the number of players in the game), and one hit kill attacks.
It would be interesting to know what tactics are out there, and how one can deal enough damage to complete the level on normal and hard.