Maxello Magic

Ask someone to think of a card, and then name it aloud any card they wish, no force. The subject is asked to truly visualize the card in their head-to burn this into their mind, you give them a lighter (or just borrow theirs). After igniting the lighter, they are asked to visualize their card in the dancing flame. You briefly thrust your fingers into the flame, wincing with pain.

For the jaw-dropping climax, you slowly turn your fingers around, to reveal the skin on your thumb and finger is now blistered in the shape of their freely-chosen card! You've just given'em the third degree!