Requires

Cast Through Time must be on the battlefield. Venser, Shaper Savant must be on the battlefield. Portal of Sanctuary must be on the battlefield. Time Warp must be in hand. available each turn.

Steps

1. Cast Time Warp 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. Activate Portal of Sanctuary 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