Najal, the Storm Runner + Wheel of Misfortune + Mindslaver

Najal, the Storm Runner

Wheel of Misfortune

Mindslaver

How it works

1. Activate Mindslaver by paying 4, tapping and sacrificing it, causing you to gain control of target opponent during their next turn.
2. Move to the opponent's turn.
3. Cast Wheel of Misfortune by paying 2, selecting an arbitrarily large number for the opponent you control, and dealing that much damage to the opponent if the oponent chose the largest number.
4. If the opponent didn't choose the largest number, Wheel of Misfortune deals that much damage to each opponent who chose the largest number.