Arcanaklepto

An empty void in your soul that feeds off of magical energy.

You have charges equal to your proficiency modifier, starting off at full capacity. However, you must roll a Con save (DC ??) every dawn or lose 1 charge. 

When you expend your last charge, the thirst for arcane energy causes you to enter a frenzy. While frenzying, you must expend a use of Fanged Bite and attack the nearest creature, prioritizing spellcasters. You cannot perform any other actions until you gain at least 1 charge. 

Notes: Incapacitated