Cast Through Time, Venser, Shaper Savant, Erratic Portal, and Time Walk

Prerequisites

• Cast Through Time on the battlefield
• Venser, Shaper Savant on the battlefield
• Erratic Portal on the battlefield
• Time Walk in hand
• available each turn

Steps

1. Cast Time Walk by paying , granting you an extra turn after this one and exiling it due to rebound
2. At the beginning of your next upkeep, rebound triggers, causing you to cast the exiled spell without paying its mana cost
3. In response, activate Erratic Portal by tapping it and paying , returning Venser to your hand
4. Cast Venser by paying
5. When Venser enters the battlefield, they trigger, returning the extra turn spell to your hand
6. Repeat each turn

Results

• Infinite turns