Both of ML have Dissociative Identity Disorder
they change into more bad guy who fell in love in a women that was a part of his trauma in the past. then they fell in love with fl...
and its really simillar story both are very good dramas with great actors

-she is not a human but he is
-she came after him to seul
-she don't have any money but he is rich
-second lead girl that likes a main male character
-she have to be close to him to live
-someone may die in the end
-very simillar vibe

-Previous lives
-same scene on the roof (i don't want to spoil)
- ghosts
similar vibe I recommend both of them

In both, the main character is police officers who secretly hide their dark side. She's plotting his revenge, while he's plotting his revenge on people who deserve it. These are also great dramas that I wholeheartedly recommend.