The World Spell, Cloudstone Curio, Strionic Resonator, Estrid's Invocation, and Altar of the Brood

Prerequisites

• The World Spell on the battlefield
• Cloudstone Curio on the battlefield
• Strionic Resonator on the battlefield
• Estrid's Invocation in hand
• Altar of the Brood on the battlefield
• The World Spell has exactly two lore counters on it
• You have at least one non-Saga enchantment card in hand
• available

Steps

1. At the beginning of your precombat main phase, The World Spell triggers, putting a lore counter on itself
2. The World Spell's third chapter ability triggers
3. Holding priority, activate Strionic Resonator by paying and targeting it, copying The World Spell's trigger
4. Resolve the copy of The World Spell's trigger, putting Estrid's Invocation and any non-Saga enchantment onto the battlefield from your hand
5. Choose to have Estrid's Invocation enter the battlefield as a copy of The World Spell, with three lore counters due to its read-ahead ability
6. Estrid's Invocation triggers once, and Cloudstone Curio and Altar of the Brood each trigger twice
7. Resolve both Altar of the Brood triggers, causing each opponent to mill two cards
8. Resolve both Cloudstone Curio triggers, returning Estrid's Invocation and any other non-Saga enchantment from the battlefield to your hand
9. Resolve the Estrid's Invocation trigger, putting it and the non-Saga enchantment onto the battlefield from your hand
10. Repeat from step 5

Results

• Infinite mill