Felidar Guardian + Altar of the Brood + Spark Double

Felidar Guardian

Altar of the Brood

Spark Double

How it works

1. Cast Spark Double by paying 3.
2. Spark Double enters the battlefield as a copy of Felidar Guardian, triggering Altar of the Brood and itself.
3. Resolve the Altar of the Brood trigger, causing each opponent to mill a card.
4. Resolve the Spark Double's trigger, blinking Felidar Guardian.
5. Felidar Guardian enters the battlefield, triggering Altar of the Brood and itself.
6. Resolve the Altar of the Brood trigger, causing each opponent to mill a card.
7. Resolve the Felidar Guardian's trigger, blinking Spark Double.
8. Repeat from step 2.