How do you get Voldemort or Tom Riddle on Lego Harry Potter?

I need someone with dark magic for the red sparkly objects of Lego Harry Potter but I can't find any cheats that give me characters, and I don't know where the floating discs are in any levels that unlock Voldemort or Tom Riddle or maybe Barty Crouch Junior or something. I'm only on like part 1 or 2 of year four, so should I ust be patient, or is there a faster way? Thanks for the help.