Beatrice has turned into this, starting out as the Card-Carrying Villain of the series, gloating over new ways to sadistically kill Battler's family and screw with his head before gradually losing her dignity and becoming one of the biggest Woobies in the series apart from Natsuhi. For starters, at the end of Ep4, she is impaled with several blue wedges but cannot die because Lambdadelta has shackled her to the game for all eternity. As a result, in the beginning of Ep5, she becomes an empty shell who can't do anything by herself — she can't eat or speak, hell, she can't even lift up a cup of tea. And to make matters worse, when Battler tries to come up with an explanation to the mysteries that denies the involvement of magic, she suffers. Bernkastel, being the charming person that she is, makes a point of saying so. And to top it all off, after having her former title stripped, she is sentenced to a rather horrible death by Lambdadelta and Bernkastel, and tries to go down laughing but ends up sounding like a human denying agony (which, sadly enough, she is), and even when Battler steps in to save her, he loses, and she begs him to not leave her alive. And who could forget her touching death scene?
And then, in Ep6, after being revived with no memories of her former self or her game with Battler, she gets treated like dirt by Battler all because she doesn't act like the Beatrice he knew. It's all you can do to not want to give her a hug. Not to mention, she was actually helping Battler all along, and just wanted him to figure out the mystery and remember his promise to her.
Rosa Ushiromiya. It's pretty hard to deny just how screwed up her life is, and, at least as far as we know at this point, how relatively little of it is her fault. Of course, it doesn't change the fact that she treats her daughter, Maria, miserably.
Eva Ushiromiya. She treats Natsuhi, her long-suffering sister-in-law, and Shannon, the object of her son's affections, like crap...and then we get flashbacked to her youth and find out that she pretty much got the exact same treatment from Kinzo, right down to the "borrowed womb" speech she gave to Natsuhi. She's one of the few siblings who is Happily Married and adores her son, but in half of the murders, she loses one or both of them and utterly snaps. In the Bad Future of 1998, not only is she suspected of murdering her family (being the sole survivor of Rokkenjima), but Bernkastel manipulates her relationship with Ange; Eva treats Ange like crap to hide the truth about her parents, and dies with Ange thinking that she's a selfish psychopath. Not to mention that she has a power-hungry Literal Split Personality who loves to make her suffer. Eva's life SUCKS. Perfectly illustrated here.
Although it's often overlooked due to inherent awesomeness, Archer in Fate/stay night is quite woobilicious and also quite the asshole. Before switching back to the good guys, his rather brutal nature is quite apparent. Even apart from any violence, his attitude and speech are also quite a bit darker and more straightforward than any of his allies. Much of this is quite Harsher in Hindsight, considering both his backstory and just who, exactly, he is.
Yet another 07th Expansion example, proving that Ryukishi 07 is fond of this trope: From Ookami Kakushi, we get Sakaki. While he may hold a horribly racist attitude towards the Kamibito, abandons Hiroshi or outright kills him in one end when he refuses to go along with his plans, and starts a town war to massacre the Kamibito in the story’s true end, he has also been put through his share of tragedy: He lost his fiancée to the old laws of the town, found her mutilated corpse, and has spent the past four years feeling as though he has no real reason to be alive other than for the sake of living. The only thing that gives his life any purpose at all, according to him, is the thought of avenging his fiancee’s murder. His arc, in particular, is a master with this trope, showing him at both his most despicable and most sympathetic.
Phoenix Wright: Ace Attorney-Duel Destinies gives us Simon Blackquill, who spends much of the game as a standard asshole prosecutor, who also happens to be in jail for murder. Then, it's revealed that seven years ago, his mentor died and he walked in to apparently find her daughter (who he was said to get along with) did it. In order to protect said daughter, he framed himself for his mentor's murder, putting himself on death row in the process and growing cold, cruel, and sarcastic during his incarceration.