Personally i would of loved an expensive (30-40) fairy guage spender that did a powerful dps attack (Fey Spear?), instead of reintroducing the, to me, annoying NRGDrain.
That way we would of been using our Aetherflow for, u know, the heals lol, promote the use of Dissipation while not taking away our heals, and give player choice in where the guage is best spent.
Atm our kit is so disjointed and using multiple things actively stop us doing other things, and this, i think, would help bring it together.

Could even add in the seraph using an aoe Spear to make use of the guage as well, and give more complexity/benefit.

And yes, i know NRGD has the use of making sure the AF guage isnt sat maxed, and a heal would just potentially add to overheal, but u could have an ability that doesnt heal but give a lowerish potency catalyse shield (Ward?) only instead as this isnt necesarily overhealing, that gives the mp regen when its hit.