Whitemane's method of healing is something Riot should explore
Whitemane in HotS heals her allies by damaging her enemies. She first applies her Zeal buff to allies, and then whenever she deals damage, allies with Zeal are healed for 100% of the damage she deals to Heroes. She pretty much can't do patch-up jobs while hiding near a Fort, as her only direct heal, Desperate Plea, costs way too much if she's forced to spam it. As such, she has to put herself at risk if she wants to get any real healing done.
A future Support Champion should look into this. Buff an ally with Q, then unload damage on the enemy and your allies will heal based on whatever damage you deal (pre-mitigation, of course). It'd fit the philosophy of what Riot wants out of healers (#NOWHITEMAGES), and fits the risk-reward system appropriately.
W
but i think it's going to be a living nightmare to balance