I'm also wondering about that too LOL. The entire series I've never seen him with a messed up appearance. Maybe because of his fighting style? though I don't know much about martial arts or fistfights in general.
I thought that too, I just found it funny because they were literally outnumbered, everyone's faces were bruised, got dirt, and my dude Suo didn't even get dirt I just hope to find out more about him, though, he is kind of mysterious to me for now. Besides, I'd like to see Kiryu as well, as far as I remember, Kiryu didn't get any dirt and bruises so far(?)
I know Suo is strong, but how the fuck everyone is getting beaten up but Suo is still clean as fuck