Requires

Hidetsugu and Kairi must be on the battlefield. Clone Legion must be in hand. Shipwreck Dowser must be on the battlefield. Mana needed:

Steps

1. Cast Clone Legion by paying , targeting yourself.
2. Shipwreck Dowser's prowess ability triggers, giving it +1/+1 until end of turn.
3. Resolve Clone Legion, causing you to create a token copy of Hidetsugu and Kairi and Shipwreck Dowser.
4. Put the token Hidetsugu and Kairi into your graveyard due to the legend rule.
5. The Hidetsugu and Kairi token's first and second abilities trigger, as well as Shipwreck Dowser.
6. Resolve the Shipwreck Dowser trigger, returning Clone Legion from your graveyard to your hand.
7. Resolve the first Hidetsugu and Kairi trigger, causing you to draw three cards and then put Clone Legion and another card on top of your library, ensuring Clone Legion is on top.
8. Resolve the second Hidetsugu and Kairi trigger, exiling Clone Legion from the top of your library, then causing an opponent to lose 9 life and allowing you to cast Clone Legion from exile without paying its mana cost, targeting yourself.
9. Shipwreck Dowser's prowess ability triggers, giving it +1/+1 until end of turn.
10. Resolve Clone Legion, causing you to create a token copy of Hidetsugu and Kairi and Shipwreck Dowser.
11. Repeat from step 4.

Results