Gogo, Master of Mimicry + High Tide + Retreat to Coralhelm + Swarm Intelligence + Doppelgang

Gogo, Master of Mimicry

High Tide

Retreat to Coralhelm

Swarm Intelligence

Doppelgang

How it works

1. Cast High Tide by paying .
2. Cast Doppelgang by paying its mana cost, targeting an Island you control.
3. Swarm Intelligence triggers.
4. Holding priority, activate Gogo by paying 2 and tapping it, copying the Swarm Intelligence ability.
5. Resolve the copy of Swarm Intelligence'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.