Heres how I interpreted it lol. Jinwoon started the game taking over Nigel's body. After all the drama happened and he gave regeneration to Inas, when Jinwoon repeated the timeline he forgot what happened and became a spirit in the original Nigel's body but the original Nigel felt something was wrong and became Glarus. Then Jinwoon gained control back of the body but since he had no past memories he believed he was the original Nigel. While Inas wrongly believes he's an outsider who's in a game characters body even though he's the original ...possibly. 