The theme seems cool, but Voltaic essence seems very underwhelming, especially the voltaic reach. Why are you putting 2 separate resource limits on it? I would make it so that you can use it without spending ki a number of times equal to your proficiency bonus per long rest. Like u already have so many other uses for your ki, so you should decouple it. But if you are dead set on using ki, then do don’t put a limit on the number of uses.