Time Wizard of Tomorrow (DLCS-EN147) - Dragons of Legend: The Complete Series Limited

"Time Wizard" + 1 Effect Monster
Once per turn, while you control this Fusion Summoned card: You can toss a coin and call it. Destroy as many monsters on the field as possible, and if you do, inflict damage equal to half the total original ATK of the destroyed face-up monsters. If you called the coin toss right, your opponent takes the damage, if you called it wrong, you take the damage.