The Sign (2023)

It's action, and the production-level is high quality. The two also has plot that are not main character-driven, meaning that it does not heavily depend on the progress of the romantic relationship between the two leads. The parallel of the two main leads of the two series are also uncanny.

Under The Skin is also a cop show with a supernatural-esque vibe, and while there is no BL, the relationship between the ML's is really great.

Both have action, a mystery and two hotties going from bickering to jumping each others bones, with love of 18+ moments between them. The Sign has a bit of a supernatural twist, but they still feel similar.

Both BL dramas include the theme of fated love from a past life and other mysterious elements - at least one of the main characters is not a regular human.

Otherworldy powers and their effects on present-day relationships
Destiny and predeterminism in relationships
Strong friendships and bonds among team members

- main characters are in the police force
- "hot" and "cool" main leads that complement each other
- mystery cases

- main leads are related to the mythical creature naga (one is naga, the BL one is reincarnation of naga)
- characters are related to mythical beings of naga and garuda
- main leads didn't remember their past lives in the beginning of the series
- third-wheel from the past

The main leads are polar opposites. Both main leads in "Killer and Healer" and "The Sign" have opposite personalities that complement each other well.