Drannith Magistrate, and Knowledge Pool

Prerequisites

• Drannith Magistrate on the battlefield
• Knowledge Pool on the battlefield

Steps

1. Whenever a player casts a spell from their hand, Knowledge Pool triggers, exiling the spell and allowing the player to cast another card exiled by Knowledge Pool without paying its mana cost
2. Drannith Magistrate prevents opponent from casting anywhere other than their hands

Results

• Opponents can't cast spells