Ride or die OR partners in crime

Taiwanese dramas:
Trinity of Shadows -this fits everything to a T. Plus it is one of the best crime dramas.
Victim's Game
The Post-Truth World

Chinese dramas:
Kidnapping Game
Burning Ice

 Reallyfan:

Which two characters exactly fit this for Trinity of Shadows?

Both.
You have 3 characters that are confronted with a case for professional reasons eg. 2 are police officers that investigate it, one is a politician. The case ends up resembling an old case that has personal connections to some of the characters, but then also gets linked to another cold case that has personal connections for the 3rd one. 

You have tremendous character development in terms of people who have their morals but end up questioning them. or betraying them. or adapting them. It goes from the typical good vs evil stance to grey. Basically what you wish to see with point 1. 

You have romance and a couple that really fights together and tries to work this out together. Where no one understands the but each other  => thing to your point 2. also closely linked to point 1. 

And you end up with an ending that is very untypical dramaland, that really questions your own take on what is fair and unfair. => back to your point 1 

Seriously I absolutely loved the drama.  In my 10 years of watching dramas, this is one of my top 4 of all time. It is really really really great, 

• The Double (she's out for revenge, he supports it 100%)
• Dong Lan Xue (morally grey, partners in revenge, very ride and die)
• Night of Love With You (both leads are villains in the story and end up very much partners in crime in the end)
• Rise from the Ashes (FL is out for revenge, ML supports it 100%)
• The Princess's Man (possibly? ML is on a revenge quest, FL is the most ride or die FL I've ever seen)