My brother and I run a emp/energy duo. When buffed, we have soft capped defense, capped regen and seemingly limitless endurance. Healing aura is our emergency "oh crud," power. This is all without IO sets. The two toons appear almost invincible and plus four bosses pose absolutely no threat.
Our complimentary build includes emp powers: healing aura, clear mind, fortitude, regen aura, and adrenaline boost. Pool powers include: assault, tactics, hasten, manuevers, tough, and weave.
However, this is a high maintenance duo. The emp buffs are relatively short in duration and you will always need to keep an eye on them. You'll know it immediately when your partner has missed a buff. It's fun, but it does gets tedious after a while.
When we need a break, we switch to our FF/Sonic duo. This duo has softcapped defense and aid self. The buffs last longer, recharge faster, and we typically only need to reapply them once per mission. They are not as powerful defensively as the emps, but you'd really never know it.
Oh, and when we a little change of pace, we switch to our fire/shield scrappers. Now that's an awesome duo too!
Anyway, have fun!
