Meteor is the spell that holds the most destructive power (yes there's also wishmagicks but those are unreliable). Scholars generally agree that there's not much point in trying to invent even more powerful spells as it already is taxing enough that only only a few dozen mages across the multiverse can cast it without severly damaging their body and/or soul.

But Meteor spreads its destruction across a wide area. What if someone figured out a spell that could take all this power and concentrate it on a small area, maybe even on a single person?