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You can tell by looking at the professors as well as the names and styles of the Legendaries that Scarlet has a focus on the past while Violet looks more toward the future. Mirai means "Future" in Japanese while Kodai, which is similar to Korai, means "Ancient". It's rumored that Koraidon is a Dragon/Fighting Legendary while Miraidon is rumored to be a Dragon/Electric Legendary, but that hasn't been confirmed as of yet. They can climb over the landscape, swim in the water, or fly in the air.
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Those who play Scarlet will have the opportunity to catch and ride Koraidon while those who play Violet will be able to catch and ride Miraidon.
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