Gantonín's Immolation

Evocation
Level: Sor/Wiz 9
Components: V, S
Casting Time: 1 standard action
Range: Close (25 ft. + 5 ft./2 levels)
Effect: Ray of flame that ignites one target
Duration: 2 rounds per caster level
Saving Throw: None
Spell Resistance: Yes

A bolt of black flame leaps from the caster's finger and engulfs the chosen target, burning them until they are destroyed.

You must succeed at a ranged touch attack to affect the target. The ray of flames does 4d6 points of fire damage and causes the target to continue to burn for 4d6 points of fire damage per round. The flames continue to burn until the target is dead, at which point the magical fires consume the corpse and go out. If the target has not been destroyed after 2 rounds per caster level, the flames go out.

Other than dispelling the flames with dispel magic or disjunction there is no way to extinguish the magical flames short of submersion in a small lake: lesser quantities of water merely reduce the fire damage briefly. A 9th level spell with the cold descriptor targeting the victim can also be used to end the immolation.

Creature that are immune to fire damage are unaffected by this spell.