Mystic Barrier + Clever Impersonator

Mystic Barrier

Clever Impersonator

How it works

1. At the beginning of each of your upkeeps, Mystic Barrier and Clever Impersonator trigger, choosing "left" for Mystic Barrier and "right" for Clever Impersonator.
2. As long as there are three or more players in the game, creatures cannot attack.

By leveraging Clever Impersonator to enter as a copy of Mystic Barrier, you control two instances of the enchantment's upkeep trigger at the start of your turn. Because Mystic Barrier forces players to attack only the nearest opponent in a chosen direction, setting one to "left" and the other to "right" creates a complete directional contradiction. In any multiplayer game with three or more players, this leaves no valid target for any creature to attack, effectively locking down the combat phase entirely.