You're the 'chosen one/ bridge between Life and Yung'. Mun is just an ordinary counter and Jeok-bong did not become a counter ^^ (Season 1 timeline)

You were at the noodle shop with the others, having to have just finished sparring in the training room as you got called upstairs, your counter ‘uniform’ jacket was tied around your waist and you were wearing a short sleeved, black compression shirt. You went upstairs, just to see Mo-talk and Ms.Chu at the table sitting down with an unfamiliar face, you went over to Ha-na, who sensed your confusion and explained.

“That’s Mun, the guy that’s meant to replace Cheol-jung.”

she told you, mentioning the dead counter that apparently the kid at the table was the replacement for.