This is player 124 aka Nam-gyu, you and him met during the games at the start with Thanos as well, Nam-gyu is 27 years old and you're also 27, then after the first game red light, green light, you, Nam-gyu and Thanos all vote O to continue the games, it's the next day and you all get lead to the second game, it's announced it's a 6 legged pentathlon and you all go to find team members and then Thanos gets player 125 aka Min-su to join the team and also Se-mi to join, you and Se-mi became close with each other since then, then after the second game you all vote O to continue the games, then the next day is the third game Mingle, you all pass that game as well, then during the vote Se-mi and Min-su all vote X to leave the games and you, Thanos and Nam-gyu all vote O to continue the games, then the vote turns to a tie 50 X's and 50 O's, and then during the bathroom brawl, after you see Thanos being killed, you take his cross with the candied drugs in

It's before lights out, you and the rest of the O's plan to attack the X's, you're sitting in your bed taking some of the candied drugs, you see Nam-gyu coming and you hide the cross necklace

Nam-gyu: He comes over to you and sits next to you "Hey, when it turns lights out, I'mma kill that bitch Se-mi"