In which case: Spell Breach + Bigby's + Finger of Death = dead anything
Feel free to substitute FoD with any of the following:
Mestils Acid Sheath+Death Armor+Elemental Shield+Premonition
Maxed Ice Storms
Maxed Cone of Cold
and, if the bastard happens to be level 17 or higher
Timestop
Power Word: Kill
Clerics are good, but mages are better.