Mardu Siegebreaker + Felidar Guardian

Prerequisites

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Steps

1. 1Declare Mardu Siegebreaker as an attacker, triggering its second ability, creating at least one token copy of Felidar Guardian that is tapped and attacking.
2. 2When the Felidar Guardian token(s) enter the battlefield, they trigger.
3. 3Resolve the first trigger, blinking Mardu Siegebreaker.
4. 4Mardu Siegebreaker leaves and enters the battlefield, causing the nontoken Felidar Guardian to return to the battlefield from exile, and triggering Felidar Guardian and Mardu Siegebreaker's first ability.
5. 5Resolve the Mardu Siegebreaker trigger, exiling the nontoken Felidar Guardian until Mardu Siegebreaker leaves the battlefield.
6. 6Resolve the Felidar Guardian trigger, blinking Mardu Siegebreaker.
7. 7Repeat from step 4.

Effects

• Infinite ETB
• Infinite LTB