I began reworking mercy some time ago (half a year?) but never finished it, the idea is to make mercy a dedicated 1 use anti-army unit with low alpha, big AoE and DoT forcing enemy to move their army out of the AoE effect. It could also be used as a Area denial weapon (ground fire in order to discentivize enemy to move through there to avoid taking dmg)
So a suicide variant of the Janis? Aeon will be the new banned faction on Crazy Rush (not that the map ever made much sense).
I'm guessing this unit would also be used to deny reclaim fields. Could be decent. May be too strong vs T1/T2 power grids though?