It’s one thing to not expect your classmate to be a superhero and not think about it. Or the random guy in the office you work at. But if Nolan Grayson is famous enough to be well known, there would have been one of those pictures comparing celebrity look alikes and he’d be found out. Even just a picture of him on the back of the book would be enough for someone to go "Hmm he looks a lot like Omni Man and it would spiral from there.
Honestly, yeah. Thula is one of the stronger Viltrumites, and once he started trying, he was kinda kicking her ass. He only lost because he couldn’t pull the trigger at the end. Which doesn’t make sense. At this point he should lose to any random Viltrumite handily.