Change soothing aura to a group buff toggle to where it heals the party members that are in range when they hit an enemy, based on animation time. Kind of like brimestone, but with healing.
Each time a player is healed with soothing aura (Or each time you do damage while soothing aura is up?) , you get a x% chance to gain a charge. Different abilities would have a normal version, and an enhanced version that'll consume charges (Think Seismic Blast). The charges could be used to incease the power of the straight heals, Anguishing Cry could add def and res to allies while taking it from the enemies, painbringer could have it's recharge time reduced, something like that.