Someone say something so I don't have to do this! Megan glances around to the rest of the group with desperation and then anger. She floats over toward where Nitro applied his talents in smashing, tilts herself so that she's basically lying down and then dangles her arms a few feet above the crater stomped(?) into the floor. Megan pauses, and turns back to Viridian. "
Are you sure you're ready? Optic, since you're not getting anywhere, can you blind her - it, whatever - by turning off the sensors for a bit?"
It's bad enough that you'll all see. "
Oh, and stand back."
After a moment's pause for people to move, she winces preemptively before unleashing her full power straight down into the hole. There's some screaming involved too.
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Round 1: Move action to float over the hole Nitro made.
Round 2: Full Round Action to break object:
Extra Effort! Barely Controlled Plasma Projection: Corrosion +
13 Area (Cone
130 ft)
Side Effect: Blast
+13
Assuming the base can't make a Reflex save

(but you never know), it loses 13 points of toughness and must take 5 on its Toughness save versus DC 28. IIRC, that can inflict a Destroy result on a 130 feet of solid steel (all that's in the area) even with the bonuses from thickness.
Shooting Star saves against a DC 28 Blast with her +9 toughness.

I'll spend an HP on improved roll to avoid Staggered, KO, Disabled, or Dying if necessary.
If there's a superscience energy reflector or something hidden inside the reinforced concrete, then spending a hero point to ensure that she evades her own blast would also be a good idea.