How about an empathy/vampire type of damage set (a bit like Rogue from x-men).
eg for a sentinel style blast set: (but I think you could make blaster/defender/corruptor sets and melee/assault sets as well.
special - the secondary damage type of the set varies according to the group of enemies in the mission/being targeted and will be whatever the most common damage type is (thats not smashing) This represents the hero's ability to use a portion of their enemies power against them.
1. ranged minor DMG (smash, special), fast
1. ranged moderate dmg (smash, Special), medium
2. ranged cone moderate (smash, special, slow
6. ranged (target AOE), moderate(smash/special) slow
8. Aim Self +To-Hit, +DMG, +Range
12. close high dmg (smash, special), slow
18. damage/heal minor dmg (smash, special) self heal, slow
22. ranged, foe stun, superior dmg (smash/special), slow
26, either pbaoe or targeted aoe, extreme dmg (smash, special) foe knockdown, very slow