Ghoul of Jack Baker.
Concept: Corrupted Priest

Background
When he was young, Brendan Callahan's town was shaken by the shocking murder/disappearance of Jack and Althea Baker, a newlywed couple who had just moved into town a few weeks previous. As a teenager, Brendan and his group of friends delighted in daring each other to spend the night at the infamous "murder house" once the investigations had wrapped up. Only one kid ever dared to take on the challenge. The kid, Jimmy White, was young and wanted desperately to fit in with the older boys, but his desperation was his downfall.

Callahan and his friends never did find out what happened to Jimmy. The plan was to let him stew for half an hour or so, then stop by with some props to scare the dickens out of the younger boy. However, when Callahan's group got there, they were greeted by the site of a very pale Jimmy standing stock-still outside of the house. He looked as though he had seen a ghost, as the saying goes, but he wouldn't say a word about what happened to him. As far as anyone knows, he hasn't said any words to this day - Jimmy ended up in a catatonic state because of whatever happened.

As Callahan was the one to dare Jimmy to stay in the house in the first place, he felt honor-bound to determine what had happened to the boy. A few weeks after the incident, he finally got up the courage to go to the Baker house and see if he couldn't figure out what happened. He saw Jack first - the sight of yellow eyes and bared fangs was enough to send Callahan screaming out of the house, which appeared to be home to a demon (as was Callahan's impression).

After failing to vanquish his own personal demon (that is, by confronting and driving out whatever had driven Jimmy mad), Callahan devoted his life to, well, vanquishing demons. He devoted himself to God and became a priest. The word of God and the holy accroutrements were enough to cleanse the Baker house, he decided, so he tried once more to lay the demon to rest.

He failed horribly. As it turns out, a gilded crucifix and a fancy outfit aren't enough to repel a vampire or to give a ghost eternal peace. It was enough to keep Jack, a highly religious man, from killing him, however.

Nowadays, Father Callahan works as a ghoul and confessor for Jack. He does his best to warn the flock away from the house, and to keep the neighborhood kids from making the same mistakes he did when he was young (for the rumors of the "murder house" still abound in the small town, and kids are still kids). He will have to leave town pretty soon - he's gotten by so far by claiming healthy living through service to God (the rumor mill suspects plastic surgery) - but he's not quite ready to leave it all behind just yet.

Notes

• My version of Father Callahan was born in 1949 in Oregon. The murders and the dare took place in 1966, when he was 17. He was ghouled in 1976 at 27 years of age. I have no idea how long it actually takes to become a Catholic priest, so dates may vary with added information.
• A hint of Jack's deformity has been passed on to Callahan through the blood - the priest has a bad case of acne; he claims that they're skin cancers.
• Ghouling Callahan was Jack's revenge for trying to wield the name of God as a weapon (though Jack would say that it was God's vengeance, through Jack) - Callahan didn't have true faith when he confronted the vampire, and this irritated the pious Jack.
• Father Callahan is aware of Althea's ghost. He may know the full story behind what happened, or he may know next to nothing. My version of Callahan has him and Althea as close acquaintances, often consulting with one another about what's best for Jack.
• What happened to Jimmy White? I ruled that the triple-whammy of seeing Jack, seeing Jack use Nightmare, and Althea's Terrify was too much for his mind to handle all at once, so it just snapped.