This is done by defeating BIG BONES. I suggest fighting him after you reach level 10. I used: Robot with the Headless Banshee stamp Knight with the No-Eyes Vampire Bat stamp Pumpkin with the Vegetarian Witches Brew stamp Big Bones will start with 4000 HP. Once he gets down to 1000 HP he goes on a sugar high. The only real difference between the two modes is that you have less time to respond to the quick time event.