im so confused. whats the plot, who is this red head

Building exploded bc nasty pervert guy got tired of Won and wanted Seongho. The little brother guy Seongho was protecting ended up supposedly disappearing with Shin, who was second in command. They’re back to the “original” base where Won, Shin, and a bunch of other guys used to live. The red head runs the original base and is pissed Won took people and resources when he dipped.