We haven't seen it happen yet, so it was off-screen as far as we know. But the earliest we've seen this be setup was at chapter 224. Then, every Christmas special after that.
what chapter in the novel does joonghyuk say "tell me you fool, if i continue to regress, will i ever meet u again?" i started reading after the demon king arc and i dont wanna miss put on that part
omg someone pick this up pls I BEGG