Cat's grace is also a good and often overlooked one. It helps with their reflex save so they in turn do not get bee's. The effects of bard songs on their attack/dmg is greater than GH so no need there, assuming your bard put max ap's into their song for attack and dmg. Displace and blur will not help against Xyzzy although it would help if some renders come in and start attacking them before they can get killed by party members.