Originally posted by -K-M-
His blasts are pretty potent even one-shotting a weakened Galactus, but I don't think that would be key to beating Superman. If Mac locks on Superman's brain pattern he literally could shut it down like he has done to others. Mac's frequency adjusting is top notch he was the only one who could power Galactus' machines and the group had people like Quasar, Sersi, BOX in it.
What's to stop Superman from creating a counter-frequency himself, as he's been shown to do on quite a few occasions?
A more likely scenario than Guardian doing all that would be Superman KOing him with a right cross to the jaw.