Only korean novels with male protagonist. 

Criteria:

The MC has to be the "bottom" (even if it's just a shounen ai, body type doesn't matter) 

The MC is smart, sharp (but not enough to realise the ML's feeling) and mentally strong (traumas are welcomed, weak side is the chef's kiss) 

The MC isn't necessary have to be a good guy. He just can't kill !!!innocent!!! people/animals/other creatures. 

The MC doesn't care about his body condition and is physical weak/got an incurable disease/suicidal thoughts (which commes from his immortality) /got hospitalised regulary. 

The MC is strong enough to fight back (with his brain or/and his "fist"). 

The ML is posessive/obsessive/kinda toxic, but definitly dangerous. Warm hearted are also welcomed,but has to be an "alpha". 

The ML tries to protect the MC, but a lot of time he misunderstands him. And get angry and anxious bc he is worried. 

The ML is also smart and "annoyingly" good-looking. ->self confident

The story must have a goal: character development/ruling the country legaly/saving everybody/curing the sick MC. 

There is min one person (usually the MC) who is reincarnated/ regressed/transmigrated/got a system. 

The place  is medieval/ fantasy/hunter themed/guide themed/omegaverse. 

Spicy scenes are okay, but fan service is a must. (that is why there are shonun ai s in the list, or novels which just give the vibe of BL)