SRD:Slay (Epic Spell Seed)

A spell developed using the slay seed snuffs out the life force of a living creature, killing it instantly. The slay seed kills a creature of up to 80 HD. The subject is entitled to a Fortitude saving throw to survive the attack. If the save is successful, it instead takes 3d6+20 points of damage. For each additional 80 HD affected (or each additional creature affected), increase the Spellcraft DC by +8. Alternatively, a caster can use the slay seed in an epic spell to suppress the life force of the target by bestowing 2d4 transform** negative levels on the target (or half as many transform** negative levels on a successful Fortitude save). For each additional 1d4 transform** negative levels bestowed, increase the Spellcraft DC by +4. If the subject has at least as many transform** negative levels as Hit Dice, it dies. If the subject survives and the transform** negative levels persist for 24 hours or longer, the subject must make another Fortitude saving throw, or the transform** negative levels are converted to actual level loss.