I don't know if was ever stated on the show or has become a fanfic trope, but it is commonly believed that Magic simply doesn't work right around Xander. This story is based on that idea. The Hyena possession was just one of the many times when there was absolutely no consideration given by the writers of the show to the implications and potential follow out from that possession. By anyone, but most especially by the sole adult in the group. The one that should have had the training, experience and maturity to know both the implications and potential damage that possession could and likely did, have. From personal experience, if nothing else. It's also become fanfic trope to explore potential other animals that they could have been possessed by. I'm going to go in a different direction. I've only ever seen one fanfic crossover and it's an unfinished one at that, the involves the books written by Lora Leigh, The Breeds. This will not be a crossover. However, it will borrow some of the concepts from that book series. Namely humans altered at a genetic level to be both human and animal. Each of these genetically altered humans eventually bonds to a mate.
Xander will be effected by the spell the zookeeper was working, but not the same way as the others. They will still be possessed. He'll be effected on a genetic level, becoming a hybrid. Not that anyone will know that for a long time. Not even him. But as a result of the change, his thinking will change, which will lead to his reactions changing. In the show, Xander could be very forceful about expressing his opinion. He'll become more so in this fic.
I think alot of people don't like his character largely because of that. He points out the stupidity of others. He questions other's choices. Fans of Buffy and Angel or Buffy and Spike want to see romance. They don't want to see creepy, stalkery way too old for the character, demonically animated corpses lusting after and influencing an already damaged teenager.
Xander's not perfect. I've never claimed he is. He's mostly a guy just trying to do his best, with absolutely no true help or support. He becomes the Heart of the Scoobies by being everyone else's support. Everyone in that group is damaged long before the show even begins, but except for using that damage as an excuse for an episode, that damage just gets glossed over. As a result of the change in Xander in this fic, he's going to be ripping the bandaids off of each and every episode that follows. And yes, the others will absolutely hate it. But they will begin to think as well. Hopefully, if I do it right, they'll all come out better in the end. It will not be a fast or easy journey, but they will get there.
Feedback is always welcome, I can't improve without it. If I offend, I apologize, that is not my intention.
Buffy the Vampire Slayer is the property of Joss Whedon and Mutant Enemy.
