Balefire

One of the most terrifying spells of the Arythian school of magic. Balefire combines the various Strands as described in Arythian magical theory into one thread, known as "Impossibility". The strand destroys whatever in touches, and can even erase it a few moments into the past if cast with enough power.

To say this is a high-risk spell is putting it mildly. The mage risks a horrible backlash with even the slightest error, and even a completely successful cast will drain them significantly. Most sane mages capable of the spell (and there are very few) will only go near it in the most dire circumstances.

The spell is rarely practiced even within Aryth, and magic-users of other traditions often won't go near it. Erasing something completely from existence is something you're not supposed to be able to do, even with magic.