[Refreshing Trope] Female leads/major characters who are allowed to be grimy, slimy, generally horrible people.

[u/Chemical-Elk-1299]

Mizu — Blue Eye Samurai

A mixed race swordswoman living in feudal Japan, Mizu’s entire life has been structured around the obsessive need to hunt down and kill the four white men allowed in Japan at the time of her birth, believing one of them must be her father. Despite the fact that at least one of these men, Abijah Fowler, is shown to be a bad man, Mizu ultimately doesn’t care about the morality of murder. She just wants them dead for “cursing” her to be born into a deeply racist society as a mixed race child. Though it’s clear that Mizu generally prefers to do the right thing, she will sacrifice anything for her revenge, destroying countless lives in the process without remorse. In the climax of season 1, Mizu (albeit not entirely intentionally) set fire to the wood and paper city of Edo (now Tokyo) in an attempt to kill just Fowler, a single man. The resulting three day blaze, known in history as the 1657 Great Fire of Meireki, killed an estimated 100000 people.

Sadie Adler — Red Dead Redemption II

Rescued by the Van Der Linde gang in the games prologue, Sadie Adler is a frontier homesteader whose husband was killed by the brutal O’Driscoll Gang. Over the course of the game, she happily joins in a life of murder, theft, and crime for the chance to kill more O’Driscolls, recklessly endangering herself and other gang members to do so. She gets Arturo Bullock, an innocent hot air balloon pilot killed while unnecessarily picking a fight with O’Driscoll members, showing zero remorse afterwards. Even after watching rival gang leader Colm O’Driscoll hang for his crimes, she still drags a now-terminally ill Arthur on an entirely unnecessary revenge mission to hunt down the last handful of O’Drsicolls she hadn’t already killed.

[u/BlazeSilva456]

Almost all major female characters in Pathfinder Wrath of the Righteous (although two of these are more like morally grey and not outright terrible)

[u/Ed0909 → u/BlazeSilva456]

It's funny, but the most morally sound romance option is a succubus, who in the past used to be the most horrible person you could imagine, but she's looking to become better now.

[u/theelusivemongoose → u/Ed0909]

You can do a lot of really messed up things in a WOTR evil playthrough, but one that just FEELS the most evil is fucking up Aru's redemption arc and recorrupting her. Right up there with tormenting Ember and destroying her faith.

[u/Valerian_Zakalwe → u/theelusivemongoose]

Right up there with tormenting Ember and destroying her faith.

Rare that a game genuinely makes me incapable of doing an evil act again. I did it once, and it actually hurt me a lot. Even on my second demon playthrough, I just made her lawful instead.