When you get to the part where you have to fight the three Vampires, take out the one on the left first. When the center Vampire is going to attack, she will make a screeching type of sound. When she does that, get ready to dodge her attack. When she uses her lightning attack, hide behind the pillar. When you take out the Vampire on the left, the center Vampire will transform. The transformed Vampire will land on the ground and remains still. Back away and do not get hit when she dives after you. If you follow this and attack at the correct times, you should be able to defeat them.