Dour Port-Mage + Temporal Manipulation + Izzet Chronarch

Dour Port-Mage

Temporal Manipulation

Izzet Chronarch

How it works

1. Cast Temporal Manipulation by paying its mana cost, causing you to take an extra turn after this one.
2. Cast Izzet Chronarch by paying its mana cost.
3. When Izzet Chronarch enters the battlefield, it triggers, returning Temporal Manipulation from your graveyard to your hand.
4. Move to your next turn.
5. Activate Dour Port-Mage by paying 1 and tapping it, returning Izzet Chronarch from the battlefield to your hand.
6. Dour Port-Mage triggers, causing you to draw a card.
7. Repeat.

This clever loop locks down infinite turns by recycling a single extra-turn spell over and over again. Every time you cast Temporal Manipulation, you bring it back to your hand using Izzet Chronarch as it enters the battlefield. Meanwhile, Dour Port-Mage acts as the engine's catalyst: its activated ability bounces the Chronarch safely back to your hand, while its passive triggered ability rewards your board manipulation by letting you draw a card every single cycle.