After a little pummeling and some more mind-sucking, Mister Terrific's true power comes into focus:
He makes his enemies feel inferior! To prove to Mister Terrific that he, Brainstorm, is not a jerk moron like everyone else, he tells Mister Terrific his origin story! Sure, villains love to mouth off about their plans. But Mister Terrific already knows Brainstorm's plans. To be able to make a villain tell you who he was and how he became a super villain on the first meeting, that's just talent!
I bet Mister Terrific isn't even very smart! He just started the rumor so that his enemies would feel the need to explain why they're so smart themselves thus exposing their secret weakness that was born with their power!
Mister Terrific uses the secret he learned from Brainstorm in such a smart way that I can't figure out what the hell he did or why it worked or how the clue made him do what he did. He must be a real genius!
Okay. Reverse the ingestion process. Got it.
His T-balls lock on to the target. To reverse ingestion probably.
And then the balls amplify his ingestion?
Oh. Um, of course! Duh!
So Mister Terrific has a problem with the solutions to problems. Maybe it's part of the gimmick!
"Hey, I'm writing such a smart character, I can make up any weird science bullshit solution! The readers won't know any better!"
And guess what? I don't! Way to go, Mister Terrific! Genius! Way to use your brain!
You're lucky the rest of the comic is well written, you technobabbling butthole.
After the battle, Mister Terrific finds out Brainstorm was responsible for his wife's death and he beats him to a pulp in front of his young fans. Luckily his T-balls produce enough electronic interference so that the beating doesn't end up on Youtube. But the kids cry and wipe off their fake Mister Terrific tattoos and Mister Terrific is left in a terrible funk for having disappointed the children.
He ditches work for a sabbatical into the Ninth dimension where, at the end of the comic, he meets these weirdos! Unless that's speciesist.
And promptly goes insane. Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn.