system
Given the following post, respond as if you're commenting on Reddit:
human
[One Punch Man] How would Saitama react to an opponent that utterly outclasses him?

so, the whole thing about Saitama is that he is powerful enough to beat everyone in one punch. this has led to him feelings incomplete and bored because all he wants is for someone to give him a good fight.

&#x200B;

but instead of  a fair fight, how would he react to facing an opponent that effortlessly outclasses him? like imagine he makes Saitama look like one of those casual villains he himself fights. like, Saitama can wail on him for hours and he wouldn't get a scratch on him while all this guy needs to do is flick his fingers and Saima is put into a coma.

&#x200B;

how would Saitama react to this? he always wanted a fair fight, but I'm not sure how he would feel about being on the other end of the power dynamic.
gpt
That seems to more or less describe his first fight, pre-OPM/Caped Baldy, against the crab monster with the permanent marker nipples. A big part of his character is that, as a certain singing cowboy would say, someone forgot to put in the quit when they were making Saitama, to the point where he's defied all known human limits simply by refusing to back away from his goals. 

In the face of that sort of certain doom, he'd stand his ground, do his best, and if he dies, he dies. If anything, that moment of actual struggle before the end would be more satisfying than any of the easy, "consecutive normal punch" wins he's racked up since losing his hair.