Kairi, the Swirling Sky + High Tide + Turnabout + Quasiduplicate

Kairi, the Swirling Sky

High Tide

Turnabout

Quasiduplicate

How it works

1. Cast High Tide by paying .
2. Cast Quasiduplicate by paying its mana cost, creating a token copy of Kairi.
3. Put the Kairi token into your graveyard due to the legend rule.
4. When the Kairi token dies, it triggers, causing you to mill six cards and return High Tide and Quasiduplicate from your graveyard to your hand.
5. Cast High Tide by paying .
6. Activate at least three Islands by tapping them, adding .
7. High Tide triggers twice for each Island tapped this way, adding that much .
8. Cast Turnabout by paying 2, untapping all lands you control.
9. Cast Quasiduplicate by paying its mana cost, creating a token copy of Kairi.
10. Put the Kairi token into your graveyard due to the legend rule.
11. When the Kairi token dies, it triggers, causing you to mill six cards and return Turnabout and Quasiduplicate from your graveyard to your hand.
12. Repeat from step 6.

This clever loop uses the legendary status of Kairi, the Swirling Sky as a built-in sacrifice outlet, sending the dragon straight to the graveyard whenever a copy appears so its death trigger can be exploited. Quasiduplicate provides those continuous token copies, while its jump-start ability lets you retrieve it from the graveyard using cards you've milled along the way. Meanwhile, High Tide supercharges your Islands to generate an immense surplus of blue mana, and Turnabout acts as the engine's untap switch, refreshing your lands to keep the chain of spells flowing indefinitely.