Can someone give me a rundown of what powers and team abilities can be used to increase the damage dealt by Energy Explosion? I'm still very unclear on exactly how this works.

SHIELD and enhancement, not perplex

Armor piercing, sort of

Yeah, pretty much what he said.

So why exactly does Perplex differ from the SHIELD TA and Enhancement?

Mostly because you must use Perplex before you declare the EE action, and SHIELD and Enhancement occur during the EE action (after the damage value is already reduced to 1). This is similar to why ICWO doesn't work; you increse the damage value by one when you declare it, and then reduce it to 1 after that.

Perplex increase's your base damage by 1, but when you declare an EE attack the damage gets reduced to 1 damage. Even if it was increase by 1 to begin with. SHIELD and enhancement work as the attack is happening so it increase the damage dealt.

I think I screwed that up a little but hopefully someone will clarify it better then I did.

So, if you have 2 V Umen adjacent to Ultimate Iron Man and declare an EE attack against a target with 3 adjacent teammates, how is the damage distributed? Is the target dealt 3 while the others are dealt 1 or are they all dealt 3?

All targets that are hit by the EE would take 3 clicks. Some may be hit while others aren't, depending on whether it hit their defense. Damage reducing powers also reduce the "splash" damage, although armor piercing can ensure that all figures hit by the EE take at least 1 click.

It gets more complicated if Iron Man in your example were to target 2 adjacent figure with EE, since he has multiple ranged attacks. Assuming that the EE hit both targets, Target A would take 3 from one attack, and Target B would take 3 clicks of "splash" damage. And Target B would take 3 clicks from the other attack, and Target A would take 3 clicks of splash damage. You add this up before applying it, since the ranged attacks are simultaneous, so each target takes 6 total clicks, which is then reduced by any damage reducers. Ouch.

In the example above, if the dual-target EE were to hit one target, but not the other, the target hit would take 3, but the oither target would take no direct damage, and no splash damage.

Note that it is a single attack with multiple targets which is why the damage is all applied at the same time.