why does he makes him suffer again???? so stupid ... poor seijin. He deserves to be loved

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he's trying to make sejin independent, since sejin was raised to be a tool je wanted Sejin to completely have a grasp with himself, make a decision, live a life.., He will leave when the time comes, that was his goal when he regressed.. his dreams are in line with the past.. so we are going near Sejin's death (in the past)