Welp, lots of your strongest summoning, remove fear casted apon your party members, weapons with +3 atleast, he's weak against fire spells (above lvl 2, fire arrow doesnt work), so get your offencive members with some fire resist and fireball him.. Other than that, u can always try the 1 guy at a time tactic, just get one of your melee to become his target, then get him in Otiluke's Resilient Sphere, though you should know it disables that party member till the spell is over.. nto to mention the guardian can always get tierd from its currect target and teleport to, lets say, your main casting charecter? [img]tongue.gif[/img]
So another thing is to spread out your ranegd guys..
Hope this helps