BL series with a red/black flag MC who’s only soft for his lover?

I’m looking for BL series from any country, especially Thai and Chinese BL!

I want one of the MCs to be a walking red/black flag, like a ruthless mafia boss, gangster, villain, or just someone who’s dangerous and morally questionable but is genuinely soft only for his partner.

My main requirement is that he DOESN’T become a completely different person because of love. If he’s a ruthless mobster, I want him to remain a ruthless mobster even at the end! I want that contrast between how he treats everyone else and how he treats his lover to stay throughout the story, not the typical “love made him a better person” trope.

Any recommendations? Thank you!