Hidden Potential

Prerequisite(s): Crystal tiefling, ability to cast at least 1 spell using a spell slot

When you cast any spell, you can channel innate magical energy into it to increase its power.

Your spellcasting ability increases by 1 (if you have multiple, you choose which), to a maximum of 20. When you cast a spell using a spell slot, you can choose to treat it as if it had been cast using a spell slot with a level equal to your proficiency bonus.

You can use this feature once, then cannot use it again until you complete a short rest.