Gogo, Master of Mimicry, High Tide, Retreat to Coralhelm, Thousand-Year Storm, and Doppelgang

Prerequisites

• Gogo, Master of Mimicry on the battlefield
• High Tide in hand
• Retreat to Coralhelm on the battlefield
• Thousand-Year Storm on the battlefield
• Doppelgang in hand
• available

Steps

1. Cast High Tide by paying
2. Cast Doppelgang by paying its mana cost, targeting an Island you control
3. Thousand-Year Storm triggers
4. Holding priority, activate Gogo by paying and tapping it, copying the Thousand-Year Storm ability
5. Resolve the copy of Thousand-Year Storm's ability, copying the Doppelgang spell, targeting an Island you control that enters the battlefield untapped
6. Resolve the copy of Doppelgang, creating a token copy of the targeted Island
7. When the Island token enters, Retreat to Coralhelm triggers, untapping Gogo
8. Activate the Island token by tapping it, adding
9. High Tide triggers, adding
10. Repeat from step 4

Results

• Infinite magecraft triggers
• Infinite landfall triggers
• Infinite LTB
• Infinite ETB
• Infinite death triggers
• Infinite blue mana
• Infinite copies of permanents you control
• Infinite Island tokens