Knuckles and The Vampire

Once there was a young bat princess, a spoiled and mean one. An Enchantress turns her into a vampire and puts a powerful spell on the castle and all who lived there. A handsome red echidna finds a castle where his adoptive father is held a prisoner of a vampire. He takes his father's place as a prisoner. Through time they get to know each other and become friends. Soon, they both realize they have feelings for each other and fall in love to unknowingly break the spell.