Cloudstone Curio, Grim Wanderer, Gwenna, Eyes of Gaea, and Tempting Wurm

Prerequisites

• Cloudstone Curio on the battlefield
• Grim Wanderer on the battlefield
• Gwenna, Eyes of Gaea on the battlefield
• Tempting Wurm in hand
• Gwenna does not have summoning sickness
• A creature has died this turn

Steps

1. Activate Gwenna by tapping it, adding that can only be spent to cast creature spells or activate abilities of creatures
2. Cast Tempting Wurm by paying
3. Gwenna triggers, putting a +1/+1 counter on it and untapping it
4. Tempting Wurm enters the battlefield, triggering itself and Cloudstone Curio
5. Resolve the Tempting Wurm trigger, allowing each opponent to put any number of artifact, enchantment, creature and/or land cards from their hand onto the battlefield
6. Resolve the Cloudstone Curio trigger, returning Grim Wanderer from the battlefield to your hand
7. Activate Gwenna by tapping it, adding that can only be spent to cast creature spells or activate abilities of creatures
8. Cast Grim Wanderer by paying
9. Gwenna triggers, putting a +1/+1 counter on it and untapping it
10. Grim Wanderer enters the battlefield, triggering Cloudstone Curio, returning Tempting Wurm from the battlefield to your hand
11. Repeat

Results

• Infinite +1/+1 counters on Gwenna
• Infinite ETB
• Infinite LTB
• Infinite storm count