Dude, the icon could be like a lightly burning hand that's been cut off just before the elbow; the hand wretched into some unseemly posture.
The aoe could be GREEN fire that pulses around the feet of nearby enemy champions, afflicting them with a dot that stacked damage over time; when use, all the stacks from any hero champions nearby would increase the next ability.
Make it a Sunfire and Scepter; no combine cost once you have both you can choose to turn it into a dual item.
-25 MR aoe
UNIQUE PASSIVE: Over time, nearby enemy champions become affected by the Hand, dealing 12 damage every 3 seconds for as long as they are in range. The damage over time increases by 4 per tick, stacking up to 5 times.
UNIQUE ACTIVE: Absorb all the stacked charges nearby, to increase the damage of your next ability by 1% per stack per champion (up to 25%).
I dunno, thats what came to mind ><