On DS, how do I defeat Voldemort (suit) and the bonus characters in the..

Ok. First, you should know that in those duels the "Y" button is to attack and the "B" button is for deflect. It is better to use those buttons instead of the arrows on the touch screen. Do Not try to cast a spell with those characters when they are not hit with the strong spells(the spells that have one of these colors: red,white, and purple). It's easier to just deflect the spells. When you deflect, always wait for it to almost hits you. That makes it go back to the caster. If he deflects be prepared for either deflecting or a chance at attack. Also, don't use a student for the battle, they have only three hearts. Use a teacher or a member of the Order of the Phoenix by choosing a character in the cauldron on the bottom floor. Voldemort is a different case. You need to make sure you are in the same direction his wand arm is in. He stands straight so he can make it confusing. His spells go really fast so you MUST be prepared to deflect.