I said "somewhat heavily centered", I didn't mean 100% like Ra-den.
In my mind this covers
Council - (Stacked for the life tear add shit + 50% of the time on Khaz overcharge, aswell as the rest of the time after sul dies)
Megaera - (80% of the healing is done during the AOE phase)
Primo - (to a lesser extent)
Iron qon - (again to a lesser extent but considering the huge amount of damage melee takes early as they get 9+ stacks as well as the final phase)
Twins - (Nuclear Explosions)
4/13 with Heavy stacking elements
3/13 with lighter stacking elements - ( but healing in these points is arguably the hardest during the entire encounter, so its valued)
But hey that's just my view!