I'd like to settle in a bit first, personally.  Though I still need to figure out how Setsuna ends up with the group; it might be easiest of Ankh hired her as some muscle, possibly recently (making this her first actual job with the group).<br/><br/>As for her background before that: Setsuna was a normal human girl until a few years ago.  She was trained in various forms of swordfighting from a young age, learning how to use several different weapons.  Sure, in the modern era swords usually didn't cut it against all the guns hitting the streets, but Setsuna was still set on learning the "old ways".  Eventually, she hired herself out as a bodyguard to various people and businesses, using her martial skill to often surprise her opponents, not expecting such an otherwise frail-looking girl to put up any sort of a fight.  That changed when the group she was with was attacked by a group of monster girls, led by a werewolf.  She fought them off, but not before being bit.  Unfortunately, she was weak with fever, and the rest of the group decided they would be better off without her, leaving her for dead.<br/><br/>After that happened, she transformed into a wolfgirl herself.  While she was able to control the animalistic instincts that came with her new form, she changed enough that no one she knew recognized her.  Her new form also seemed to have trouble with the swords she used to wield so effortlessly, until she found a massive blade, larger than any sword she had wielded before.  For some reason, she was able to use this sword just as easily as the others she had used previously, and decided to take up her old bodyguard job.