They're from another world, called the Fusion Dimension and they come from a school called 'Academia' that apparently train dueliest soldiers. They were the ones that were responsible for the attack on Yuma's home, as well as an attack on Yuto's home, which resides in another world, called the Xyz Dimension.
From what I've seen, they possibly use their duel disks to jump dimensions. I saw someone be sent back to Academia that way, so that's why they seem to appear out of nowhere.
Re: [Festival Area - Jungle Zone]
They're from another world, called the Fusion Dimension and they come from a school called 'Academia' that apparently train dueliest soldiers.
They were the ones that were responsible for the attack on Yuma's home, as well as an attack on Yuto's home, which resides in another world, called the Xyz Dimension.
From what I've seen, they possibly use their duel disks to jump dimensions. I saw someone be sent back to Academia that way, so that's why they seem to appear out of nowhere.