The Defender already has that with their melee power. You can set it up for buffs to other powers, or to just regenerate its over shield. I do wish the striker had a choice from its melee to significantly buff any damage done for a period after a melee kill. Or a super almost like sunsinger that makes your health skyrocket, increased damage, and something to do with infinite ammo for your guns for that period. There's a perk similar in mass effect 3 that was great in the mp. Might be pretty op in crucible though