Aurora:
Considering that from max MP a Paladin can cast 5 successive Clemencies with no cooldown to speak of (not that they ever would or would want to), I find GNB's Aurora -- which is equivalent to roughly one clemency and sits on a 60 second cooldown -- to be pretty lackluster. However I don't recommend changing the cooldown for Aurora to compensate; I would recommend changing Aurora to consume a cartridge and maintain a cooldown equal to the effect of Aurora's regen (18 seconds) so that ability can't be stacked by one GNB. As it stands abilities such Bloodfest act as basically just a DPS dump and would have zero utility in a defensively hectic situation. Furthermore GNB's cartridge system has already been criticized for being too simple and bare-bones. Integrating at least one defensive ability into GNB's cartridge system would make the decision making of spending cartridges much more meaningful -- because as of right now it's not at all.
Lastly, I would also advise that any over-healing done by Aurora be stored in a shield. Heals right now can feel pretty bursty, and if I've recently popped Aurora and am healed to full, then that's a waste of 60 second cooldown. Allow this shield effect to be transferable to party member for an appropriate period of time with HoS.