Actually, I think Disney's Brave would make an awesome Ravenloftian scenario, with the right adjustments.
http://disney.wikia.com/wiki/Mor%27du
That's about as Ravenloft-y as it gets, I think.Mor'du was once a human prince, the eldest of four brothers, all the sons of a wise king beloved by his people. The youngest brother was wise, the third brother was compassionate; the second brother was just, and the eldest brother, Mor'du, was strong, but he mistook great strength for character.
One dark autumn, the king grew ill. On his death-bed, the king requested the kingdom be divided among his four sons, so together they could be the pillars that would hold it together and maintain peace.
Alas, the first brother felt that, as the eldest and the technical heir, he alone had the right to rule the whole kingdom and a seed of selfishness grew in him like a poison.
To his brothers he claimed his right to rule and demanded their obediance, shattering the bonds of their brotherhood by breaking the family stone.
Words turned to war. Brother turned against brother in a war fought on four sides that changed the kingdom forever. While the eldest prince commanded a powerful army, the battle remained a bitter stalemate.
Starving for victory, the prince cursed his fate and stalked the woods until he came to an ancient circle of stones.
The Will-o-the-wisps appeared and led him to a dark loch where, not far from the shore, was the cottage of a witch. He demanded from her a spell that could change his fate.
The strength of ten men he desired, and to persuade her he offered his signet ring. The bargain was struck though the Witch could see his wounded soul. She completed the spell in the form of a potion but offered him a choice: To fulfill his dark wish or heal the bonds of family he had broken.
The prince baited his brothers with the false promise of truce, but when they met in their father's throneroom he once again declared himself the sole ruler and demanded their obedience.
When his brothers defied him again, he drank the spell, which immediately took effect. To his surprise however, it transformed him into a great black bear. Only by mending the bonds torn by pride could he break the spell. Instead he accepted the form of the monster and slew his brothers in cold blood.
He returned to command his army but they saw only the dreaded beast and so turned against him. He slaughtered a great many while the rest fled the kingdom in terror.
With the armies of the brothers fractured the kingdom fell to darkness and ruin, and the blight of the Great Black, Mor'du, fell across his domain.
Desiring power for over the bonds of family, Mor'du had changed his fate for the worst, doomed to wander endlessly, his soul forever buried in this scarred and tormented shell.
Actually, I wonder how much of the story is really rooted in real Celtic mythology; a few years back, I played in a Midgard campaign (the German oldschool RPG, not the Pathfinder setting) that featured a very similar plot.
