How to Get the Last Locator Card in "Yu-Gi-Oh!: The Sacred Cards"

There are a total of six Locator Cards in the "Yu-Gi-Oh!: The Sacred Cards" video game for the Nintendo Game Boy Advance. You can obtain the sixth and final Locator Card by defeating a mysterious duelist known as Mako Tsunami. Other duelists allude to him as being a very powerful duelist who hangs around the Aquarium. Before you can find and duel Mako to get the last Locator Card, there are several tasks you must complete.

Play through the game until you have defeated Weevil Underwood three times. Go to Clock Tower Square, which is near the center of the world map. Once the area loads, go down one screen and to the right until you reach a somewhat open area with a single person there.

Speak with the lone man and he will duel you. Once the duel is complete, he will tell you that something strange has been going on at the card shop. Exit Clock Tower Square and go to the card shop, which is to the southeast on the world map.

Speak with Arcana, the strange man at the card shop, to initiate a duel. When the duel is over, three new areas will be unlocked, including the Aquarium. Exit the card shop after the cutscene and head to the Aquarium.

Explore the entire Aquarium and defeat every single duelist there. Once you defeat the final duelist, Mako Tsunami appears. Defeat him in a duel to earn the final Locator Card.