!!th: Mage's Pinnacle

Mage's Pinnacle

You have mastered the greatest secrets of magic, coming close to being able to pull on reality's strings.

you gain a single 10th-rank spell slot, and can use it to cast 10th level spells or lower. If you already have a 10th level spell slot when you gain this feature, you gain another. You can't use 10th-rank slots with abilities that give you more spell slots or that let you cast spells without expending spell slots