They are symbolic of how they lived.

Everyone’s ending rhymes with their method of harm.

Chan-u stole stories, so his own story becomes haunted, and he is haunted psychologically by Yu-min, and materially by Seung-gyu.

Yu-min was killed by Chan-u, because even if it was for revenge, he still became a monster in the process. The silver lining is he can haunt Chan-u from the grave. He made revenge his identity, so revenge consumes and kills him.

No-ja used violence as practical labor, so he loses ease of violent labor (nerve damage in arm). Taking away his arms takes away his tools to bury or harm others, and forces him to live a mundane, if bothersome, life.

Nobody gets a clean reset. Nobody gets full absolution. Even survival is compromised.