[@Golem] But hey! What's more mysterious than a close-mouthed man who seems to suffer under the daylight rather than under the whip, who takes whips with barely even a flinch, and yet is constantly disappearing and reappearing during the workless times? Someone could find some dirt on him- such as him being a vampire- and force him to join and help the ragtag group of slaves to escape, otherwise be turned in and hunted/killed in the unfamiliar desert. You want character development, no? He's forced into a group and slowly begins to like and/or care for them, or maybe he just hates them more but gets conflicted. I dunno. We're all slaves, right? What's the difference between a slave that's been broken by it and a slave that's immortal but has been whipped so many times he cares for little but a childhood passion? 

Or something.