Pizza Wizard

You are working as a pizza delivery man and you get an order for the mysterious dude who lives on top of the hill outside of town. You drive there, pizza in tow, and find a castle, and a wizard! The wizard tells you, "TO GAIN GREAT FORTUNES," (You say, "you mean a tip?") "YES. COLLECT THE 12 SLICES OF THIS PIZZA AND REASSEMBLE THEM..." ("OK?") "WHILE AVOIDING ME AND MY LIGHTNING! (Maniacal Laughter)"

(can you find the secret ending?)