When you activate Sorcerer Mickey's skill the screen will change and you will see a silhouette of Sorcerer Mickey in the lower left corner. To the right of him will be sorcerer hats. These hats indicate the number of times you can click in the screen to clear Tsums. Each time you tap it will clear the Tsums around the spot you tapped and one of the hats will disappear. Once there are no more hats gameplay goes back to normal. Increasing his skill level either increases the number of hats you get or increases the radius of Tsums you clear with his skill. The number of Tsums you clear with a click stays small for all the hats except the last one. The last click clears more than the others so it is best to click in the center of the screen for the last click. For the others, it is best to click in different areas so that you get the most Tsums per click. Most of them will generate bubbles so you will end up with a bunch of bubbles to pop after you have used all the hats.