Asylum shade lich..., Skeleton Lord's are tearing my tanks a new one! Options

[olimikrig]

Tried everything I can think of here.. The lich itself isn't really that much of a problem, the skeleton lords, however, are simply just too much for my front-liners. They are tearing my tanks to pieces within seconds. I don't really understand just wth is going on, I've dealt with other skeleton Lords before, and they weren't too much of a problem (the planar sphere demon fight amongst others).

My party is (all lvl 13-14):

Vagrant
Berserker
Anomen
Valygar
Nalia
Imoen

Heck, I've even tried resorting to some cheesier tactics, bottlenecking the Skeleton Lords in the corridors back towards the crystal area, but I still only seem to be able to get one of them down - at most - before my melee guys start dropping like flies.

Any help would be greatly appreciated as I'd hate to have to end up resorting to lowering the difficulty.

[olimikrig]

SPOILER!

Yeah that's also how I did it, problem was just that by the end of the fight my resources had run out, the summons were gone, and Valygar's buffs had run out. So I did not have much of a choice but to move all in and make an attempt at finishing it off quickly

On a side note I now officially hate all the "helpers" in the Irenicus fight. They just ganged up on him and stood there doing nothing but preventing my guys from getting in... Never really realized how annoying they were before since Irenicus usually goes down in a couple of swings .