Guessing that the guy is a real person/professional gamer due to the more realistic style, but since I don't really follow that kind of thing no idea who he is.

looks like tokido

gyaru's about to get raging demon'd

Yeah, from replies in the Twitter thread, it is apparently Tokido (I went ahead and tagged them appropriately). Can't say I follow the Street Fighter scene enough to know who he is either.

Even though she's using a different character here, I really hope Osanai was the one handing Otaku his ass online too. I was hoping there'd be a later reference to it being one of the girls after that was posted.

Interesting how close Kinjyou and Osanai's likability levels are right now...

Hahahaha, it definetely is Tokido. Hope to see Fuudo and The Beast.