Extraordinary Effort/Last Ditch Effort are once per story uses of Extra effort that allow a character to spend everything that they have left, All hero points, and all status conditions Fatigued, Exhausted, Staggered, Disabled, Unconscious, Dying, and Dead. The rules are in the Mastermind's Manual, its intended for dramatic effect, the defning moment of a character's career, Spiderman trying to stop the runaway train in Spiderman 2 and passing out from the strain.
Mastmind's Manual said:
Extra effort and hero points allow characters to accomplish a lot. However, there are those times when even extra effort isn’t enough and extraordinary effort is called for.
So a hero could gain up to five additional levels (beyond Fatigued and Exhausted), but it means the character dies at the end of the effort. Last-ditch effort is usually reserved for truly dramatic situations where the heroes sacrifice all in order to succeed.
I honestly don't think even going with a +29 damag bonus would (10+18) would do much to Cardinal, but as an area blast it might drop Metatron (43 DC Tough Save) and whoever it is trying to knife her in the back, but either way it would be a very Kelly thing to use up everything in one blast and hope she succeeds. Without doing that she'll be spending the hero points on Ultimate Save and being completely ineffectual on offense until she runs out of HPs and goes down. She can't run, and she wouldn't even if she could, so its stand and fight until she dies or Cardinal loses interest.
Having Kelly just swing away at Cardinal ineffectually just isn't that cool, and her saves are probably to the point that Kelly can't affect her with other saves. It'll take some thought, though I am curious as to why Cardinal thinks Kelly knows where Cassie is, I mean Caridnal has thugs searching the school, obviously She knows Cassie is at the school so trying to convince Kelly to tell her where Cassie is kinda of pointless.
