Encroaching Mycosynth, Daretti, Scrap Savant, Spark Double, and Felidar Guardian

Prerequisites

• Encroaching Mycosynth on the battlefield
• Daretti, Scrap Savant on the battlefield
• Spark Double in the graveyard
• Felidar Guardian in the graveyard
• You control an additional nonland permanent
• At least three loyalty counters on Daretti

Steps

1. Activate Daretti's second ability by removing two loyalty counters from them, sacrificing any other nonland permanent and returning Spark Double from your graveyard to the battlefield
2. Spark Double enters the battlefield as a nonlegendary copy of Daretti
3. Activate Spark Double's second ability by removing two loyalty counters from it, sacrificing Spark Double and returning Felidar Guardian from your graveyard to the battlefield
4. Felidar Guardian enters the battlefield, blinking Daretti
5. Repeat, sacrificing Felidar Guardian in step 1

Results

• Infinite ETB
• Infinite LTB