That guy is super-annoying. He speaks faux-Korean and screams "Nana strong!"/"Mother Korea!" whenever he succeeds at something. His ping is not Korean, of course. More like Polish or German. During this game http://pantheon.demigodthegame.com/game/2102076/player/200037/ I did not heal him on purpose to gauge his true command of English. Surprise, surprise! It's much better than his usual entirely non-funny babblings.
To me, he sounds like Red-One/Annon. The same - almost schizoid - clinging to a stupid imaginary persona. He's also obviously not a noob player, but see his game list -- he's not above noob-bashing, which is rare among pro players (99% naturally find it boring). However, as we all know by this point, noob-bashing is the activity One team guys always excel at.