Sheesh - the wight can suck HP twice in a single round? I smell limburger.
Wish I had been able to use my action point to shoot him again before he could do that, but with reload as a minor there was nothing I could have done there.
I'd say everybody needs to unload on the wight with everything we've got left - Thurnan probably can't take another round of double sucking.
Assuming Tanthalus can get Dunor up again, is there a rogue power he can use to shank the wight with flanking? Galadren is providing flanking so that means Combat Advantage/Sneak Attack. As a cleric does Tanthalus get the Turn Undead usage of Channel Divinity? Or was that Divine Glow encounter last turn the "Channel Divinity" usage?