transmigration manwha where mc is ruthless and not afraid to kill (i'm ok with pseudo-harem, like many girls like him but he only go for 1 girl. no harem would be best tho)
Recommendation(▰˘◡˘▰)
1. How to Live as a Villain
Probably one of the strongest fits for a calculating, selfish MC who prioritizes survival and doesn't hesitate to use people. It has a survival-game setup and morally ruthless decisions. Romance and harem aren't its main appeal.
2. The Heavenly Demon Can't Live a Normal Life
The MC is reborn into a nobleman's body and is extremely confident, strategic, and ruthless toward his enemies. Fantasy warfare, political conflict, and power-building. Romance isn't the main focus.
3. Kill the Hero
A calculating MC seeks revenge and uses his knowledge to eliminate his enemies. Very little romance and no major harem focus. It's regression rather than transmigration, though.
4. I Am the Fated Villain
This is technically a manhua, not a Korean manhwa, but it fits the transmigration and genuinely villainous MC requirements very well. The big drawback is the harem-like setup, with multiple women interested in him.
My picks: Start with How to Live as a Villain for the ruthless personality, or Kill the Hero if avoiding harem is your biggest priority.
it's a cultivation novel, one thing i remember there was an arc where ml became blind after an accident then mc take care of him by pretending to be a woman but ml still figure it out after a few days. ml is supposedly some womanizer (?) but haven't conquered any of the woman, so mc take the role of one female lead in the original story by taking care of ml

bl with prominent chasing arc? preferably with little to no smut (like The Nameless Flower)