I'm looking for a story that I've read a while ago and it's been driving me crazy that I couldn't find it. It's either a manhwa or manga.
Here are some of the details I remember:
- The story is set in (hell?) / hellish surrounding.
- I remember the main character as someone who capable of body possession or soul transferring ability.
- The main character can see the level or grade of a person body.
- the main character is weak (and forced?) to serve some stronger master.
- I remember there is a test tube containing a body of his master but it was stolen by a guy.
- There are instance where the main character had to fight the body thief where he at the brink of losing because his "body" reach his limits but not his soul.
Possible related theme: survival, demon like people, dark