The Last Word

The Last Word is arguably the most powerful spell in existence. It was used by Orcus to defeat the likes of Primus in order to find his wand. It is so powerful in fact that the mere knowledge of it is enough to slowly destroy even deities who possess it. For this reason, if your god offers you the Last Word you should probably start looking for another god. The Last Word is capable of unmaking any being it is used on, including greater powers.

Any creature the Last Word is used on it erased from existence.

A creature of CR 30 or higher may gain access to last word as an arcane spell or ability. This creature will slowly be unmade in an amount of days equal to its CR.