black_z

Why is he still on chains even after coming back?

Since you are on ep 7 it will be revealed that the crown prince also have the ability to hear dead like the female lead. He heard from the dead how the fl's mother and the grandmother killed all of king' s brothers. He kind of kept his ability a secret.
The crown prince was after the throne and killed two of his elder brothers by poisoning .The king came to know that and killed the crown prince by poisoning since he doesn't want another king to sit on throne who killed his own brothers.
The youngest prince was killed after he became the evil spirit