Going to be honest the first part of the description wouldn't work. How would you be in a rift with full class energy? Unless you're in another warlock's rift that would make sense but then you would have to depend on other warlock's to drop their class ability. Other than that if that first portion is removed then that is an awesome idea.
English
-
Fun fact that's how it works now, I just tweaked some of the wording I believe. But also that's why In the tweak to the exotic it would be able to have two charges so you use one charge then can activate with the second. Plus the first rift would be giving you 200% class ability Regen (or whatever is reasonable for class ability Regen)