On Topic: Vash the Stampede also has a pretty traumatizing past.
Lelouch was pretentious as fuck but from what I've seen (the first, 14th, and last episodes) he's a pretty okay guy.
all of the characters in one piece has an emo past life.
You don't seem like an intense dude, so interesting choice. Sort of like Jubeh... I mean, Cooking Mama is really, really intense!
The Nameless One or Deionarra from Planescape: Torment
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Kotomi Ichinose from Clannad. Everyone from Angel Beats. P. much all of Key's characters have sad past lives.
Revy from Black Lagoon.
Clare and Raki from Claymore.
I could continue forever. Angel Beats is cheating a little bit though, since you have to have a crappy past to be put where they are.
Arseface from Preacher.
Ok, the kid lived in a abusive home and he loved Kurt Cobain, he love him so much that he tried to kill himself as Kurt Cobain did; with shotgun at his face. Sadly he fail in his suicide intent and his face end deformed, looking like an ass.
He lives with his father who is the Sheriff of the town, sadly his father never speak to him or see him to his face, but he still love his father, he talk to him, he tell him his wishes and aspirations, but his father never looks to him or speak to him, like if he wasn't there.
Then Jesse force the father of arseface to fuck himself, which he did, chopping his dick and putting in his ass. After this the paramedics appear to save him, the sheriff tell to his son for his gun. Happily his son (arseface) gave the gun to his dad while telling him "that is great my father has spoke to my! maybe we can be a family again, maybe we can be happy again" but after he gave the gun his father blows his head.
In that day that little kid become Arseface.