When Ethan Rayne finished his plea to Janus, when he felt the power coursing through him, he laughed. He thought about ghosts and monsters and a total inefficent slayer. But there was one thing he hadn't even wasted a thought for.
In all his work and research for this night, he never thought about the possible effects the spell would have, if someone dressed up as a real and still living character. Why should he? After all, he believed the costumes to be all fictional. Well, most of them where, but one costume, worn by one Xander Harris, unfortunately did not fall into this category.
For him, the changes of his body would remain, even after the end of the spell, since the power of Janus didn't have to invent the physical matrix along which he was changed. It simply copied the matrix of the original and with that much power left over and the fact that the matrix was a real one, the change became permanent. Similarly the memories of the original were copied and dumped permanently into his brain, to merge with his real memories in one set.
Had Ethan known about all of this, he would have tried to find as many true costumes as he could, but he would also have made sure to burn this particular one. Yet, since he had no clue, he was simply laughing as Janus power changed destiny.
Xander sighed as he left the crypt. Ever since the chaotic helloween he felt better sleeping in a crypt... sleeping in a coffin to be exact. And after displaying his new powers to the local vamps, he was left alone during his sleep. His powers... a lot had changed since that night, his diet, his looks, his race. All because one chaos mage didn't bother to research his spell correctly.
Well, if he hadn't let Ethan talk him into this costume to impress Buffy, none of this would have happened, but it was too late now, to worry about this.
Instead he should worry about this uneasy feeling he'd for the last few nights, as if someone was searching for him.
Then he saw IT. A huge black castle, slowly taking form, at the outskirts of the city.
He cursed and ran towards the libary, his long, wavy, brown hair fluttering after him, not unlike a flag.
This was not good. He could claim to say that this was really bad. How could he explain all that had happened to the owner of that castle, the one that was especially here for him?
How could he survive telling Buffy and the other Scoobies, that Dracula had come to take his wayard son home?
from Konamis CastleVania: Symphony of Darkness
Adrian Farenheight Trepes, dhampir, Son of Dracula