Some fanbrats just love to try to redeem the villains of their favorite fandoms. 99% of the time, this is done because the actor who played the villain in question was teh sexy!!!11eleventy! in the fanbrat's view.

Now, I'm not saying that redemption fics can't work--they can, and I've read some good ones. Far too many, however, redeem the villain through massive OOCness and WTFery.

Some common examples:

Draco Malfoy (it's not called Draco in Leather Pants for nothing) and Snape
Darth Vader (in stories having nothing to do with Luke bringing him back to the light)
The Phantom of the Opera

What do all these characters have in common? They're all played by actors who make fanbrats' little hearts go pitter-patter and get damp between their legs.

Occasionally, you'll find a redemption badfic that breaks this mold, like a Star Wars fic I read years ago in which Palpatine was turned to the light side of the Force with hawt buttsex with Anakin.

There are a few main causes of redemption, among them:

1. Hawt sex equals redemption ('cause we all know sex can fix anything).
2. The slightly more character driven, but nonetheless still awful power of twu wuv (typically, the villain falls in deep, everlasting love with Marietta Susanna Manzanita Appleblossom Happyface Internet, who removes his real personality and turns him into a Stepford good guy).
3. Death equals redemption, i.e. "I burned down twenty major cities and murdered the survivors because they looked at me funny and dyed their cats' tails purple, but I did it all for love/because I was abused as a child/fuck why here's an incredibly valuable object/piece of information/sad look, and I am now a good guy, so everyone will mourn me and I will become a legend for all the right reasons."

I've run across one even odder than that: redemption by CANON LIES AND HE WAS A GOOD GUY ALL ALONG AND WHAT YOU SEE ON THE SCREEN IS FALSE.

I read a Titanic redemption fic once that basically turned Cal Hockley into an Edwardian emo kid.

I'm a huge fan of redemption fics and always go to look for some when I get interested in a new fandom. Sadly, it's not very often that I find something worth reading. As mentioned, too many stories assume that falling in love automatically deletes all past crimes. If the villain falls in love with a good guy, it's more than likely that the other good guys are turned into evil assholes. In fact, I wouldn't really even call these stories redemption fics since the villain never regrets their actions or has to pay for them. Instead, the canon good guys are turned into villains.

My favourite kind of redemption fics are entirely or almost gen. For many villains, dealing with what they've done is already such a huge task that I don't think adding romance to the mix serves the purposes of the story. At the very least, the villain should be well on their way to redemption before romance starts playing a part in the story. Secondly, I don't want any excuses for the villains' actions. Even if they were committed with good intentions, the villain has to deal with the consequences. Lastly, the good guys shouldn't forgive the villain right away with no conflict whatsoever, and the story shouldn't read as if the good guys don't have the right to feel resentment or mistrust.

Redemption fics are good, as long as you go about it in a manner that doesn't seem forced, and face the facts; not all villains are concievably redeemable.

Most characters can be at least brought to a stage of decency - the power of love is confirmed to be a powerful sonuva bitch. But they can't all be good guys.