This was definitely a very close battle. Yuma is the main character of Yugioh Zexal and he has quite a lot of monsters at his disposal. His Utopia has several forms and each one is stronger than the last. Unfortunately, most of Yuma’s other fighters are not nearly as powerful. Even the legendary numbers tend to only be decently powerful with a few exceptions. Kai’s array of monsters is definitely a lot more limited, but they tend to be a lot stronger than Yuma’s. (I’d say that Cardfight tends to have the stronger cards, although Yugioh top tiers are still top tier) Kai’s Dragonic Overlord and Nebula Lord cards should be enough to take out most of Yuma’s army and his other fighters can help to pick off the rest. It’s a close battle, but there is a reason why Kai is known as a Cardfight Master! Kai wins.