Ilmater's Fist

This spell brings into being a spectral flying fist. This flashes through the air to unerringly hit a single chosen target creature. The fist deals damage to the creature equal in hit points to all damage suffered by the caster (from all sources and ignoring healing magic that may have been applied) in the preceding hour. Having delivered its lone attack, it vanishes.

The flying fist fades away harmlessly if the target creature passes beyond spell range or if it comes into contact with a dispel magic effect or a continuous magical barrier. (It can find its way around barriers that do not seal against solid walls or surroundings.) Once the casting is completed, the caster of Ilmater's fist cannot change the chosen target.