SOLVED. A man who was a slave is possessed/joined by a demon that he loses control over [s]

[Kody]

I read part of this book around 2007. I have no idea when it was published. I think it was a series that I accidentally jumped into the middle of. There was a man who was possessed by a demon that he sometimes lost control over. He savagely killed someone when that happened. I think he picked the demon up in a desert as part of some ritual. He was a slave at some point before this book began, but he escaped. You could tell who the slavers/slave hunters were based on the side of their head that their braids would fall. I think he was branded as a slave as well. He had a serious wound in his side at some point before this book and he couldn't raise his one arm up very high. At one point he is able to summon a wall of fire (I think it was just an illusion) so that he could escape someone (maybe a group) that was pursuing him. I don't think these things happened in the order that I posted them, but they are the major points I remember of a book I could never finish. It fell out of my car when I was travelling. Thank you,

[infael]

Sounds like "Transformation" by Carol Berg.

[Ann aka Iftcan]

Transformation for infael's clicker.

[Kody]

I think that might be it. I was a little fuzzy on some of the details, but this seems right. Thank you very much infael.