Force Mortality (3.5e Spell)

The earth elemental began to decay rapidly before your eyes before crumbling into a pile of dust.

This spell only works on creatures which are immortal, such as many elementals, outsiders, constructs, and undead. It also works on True Dragons who, while not immortal, gain power in age instead of losing it. Those that fail the Fortitude save take penalties as if advanced one age category used for humans (that is, Middle Age of -1 physical scores and +1 mental scores). You can continue concentrating on the spell, advancing aging by a category each time to venerable. A successful save negates the aging for this round. This applies to True Dragons rather than their normal age category benefits.

If a venerable creature fails the Fortitude save they die as if from old age. If the creature normally respawns (such as a lich) they must succeed on a character level check opposed by your caster level. If they fail, they do not respawn.

Powerful as the magic is in enabling death to immortal beings, they cannot keep them dead forever. A creature who dies remains dead from old age for 1 year/caster level. After this, they remain dead but can return with their usual respawn methods (such as a lich) or can be revived by normal means (as if they were killed and not dead of old age). A wish or miracle can also reverse the death by old age effect, allowing them to be revived as normal.

Focus: A pocket watch set to move too fast, valued at 250 gp.