I like the idea of making Invigorate something which is able to be used repeatedly over the course of the game, but for it to be balanced, you would either need to increase the cooldown time (probably to 3 turns) or else make the effect buff a random unit in your hand instead of one you choose. If it was a straight copy of Royal Inspiration, it would almost definitely be broken. Buffing cards in the hand is strictly better than buffing cards on the field. Unfortunately, this entire conversation is probably moot. I don't see CDPR making any large changes to the game in the foreseeable future. They seem to only ever adjust the provision limits of leaders, and even that is done sparingly. Still, it's nice to dream.