I've been trying to re-work the revived subclass into a Warlock class. Ethereal Jaunt can just be cast misty step at will. Need to replace Bolts of the Grave with something else though. On a warlock, perhaps it gives the Agonizing Blast Invocation for free but changes the damage type of your EB to Necrotic damage. I think that would be reasonably balanced. Free up an invocation essentially at level 3 with a small tradeoff in damage type.