[Faceman]

on topic:
sometimes Greater Wolfweres fall easy enough but under some party setups there might be problems, so what lvl and classes are your party?
If nothing helps treat it like a boss fight you can't win:
hit it with lower resistance a few times and after Greater Malison and Doom use some insta-kill tactic (e.g. Disintegrate, Flesh to Stone, Finger of Death, high level Chromatic Orb,...) or stun it and hack awayas fast as possible
OR
Haste your party and Slow the WW, remember that you need magical weapons to hit it (especially when using ranged attacks, as I guess your tanks are magically equipped anyway)