That is really scary ability, ghelas. Outrageous even.
Here's an idea for a DM Skeelz
Power = Opp Power + Opp Damage
d"Amaaj is a pacifist and, thus, appears an easy target. Adding to this, his classmates have powers over earth, wind, fire, etc. and d'Amaaj has power over heart. But in this case, heart means turning attackers against themselves, subduing them with their own emotional and mental vulnerabilities. Who said heart was a lame power?
The ability works like this: d"Amaaj' power is the total base stats of his opponent. Against Cortex, he's a 16/6! Against Dreen
, he's an 8/6, but loses three of that power to her ability making him a 5/6. 9/6 vs Jose Star
. Wildly unstable against low stars, but he shines against high stars.