Responses
Based from what I seen, he seems to remember everything right after they both are in that very situation where he needed to die. Remember when he state “now I remember” and decided to jump off the cliff cuz he knows, eventually, mc is bounded to him in one way or another. Take the pile of corpse as an example.

When did Guwon know about that cliff? Like did he knew it all along every reset and is just playing dumb until the situation requires him to divulge it?
Also, since there's lots of Teach's corpses on their he must've tried gazillions of times. In this resurrection, he remembers what happened in the past. Does this mean he has gotten amnesia on his last death bec. he didn't remember anything?