Inalla and Sidisi's Faithful Infinite ETB Triggers

Step 1: Cast Sidisi's Faithful.

Step 2: Use Inalla's ability to pay 1 mana and create a token copy of Sidisi's Faithful with haste.

Step 3: The token enters the battlefield, triggering its exploit ability.

Step 4: Exploit the token itself to trigger its effect and sacrifice it.

Step 5: Sacrifice Sidisi's Faithful to Ashnod's Altar to generate 2 colorless mana.

Step 6: Repeat the process by using 1 of the colorless mana generated to create another token copy with Inalla's ability.

Step 7: Result: Infinite ETB triggers, potentially infinite damage or mill with additional cards such as Impact Tremors or Altar of the Brood.