Leon Soryu
Leon appears leading Team Dreadnaught. He wants the world to remember the name of "Soryu" and show them the power of Aqua Force. While he plays by the rules, his allies and teammates are just pawns to used and discarded at a moment's notice, so he has a mean side that'll do anything to achieve his goals.
About Season 2
With Season 2, there's an attempt to avoid making the story too long to follow or overarching, and there's more focus on the card fights.
The story of Kai leaving Team Q4 was decided a long time ago. Kai was ridiculously strong though, and thus the other members constantly relied on Kai without getting stronger.
Aichi & Kai's Relationship
Until now, Aichi has been following Kai, who was originally intended with the position of being his rival. So if you want to know how their relationship will develop in the future, there *may* be a sudden shocking development.
In Episode 2, Kai told Aichi "I have to go my own way", and left Team Q4. At the time of Episode 2, it meant something different. While Team Q4 went to Singapore, Kai was on a mission of training, searching for strong opponents, and while doing so, Tetsu spoke to him, which lead to him joining Team AL4.
Aichi & Leon's Relationship
With Leon and Aichi's relationship, there's the intention of showing how these two contrast in many ways. Aichi for example, values every card in his Deck and every member of his team as being near and dear to him.
But for Leon, everyone and everything is just a pawn to be used. They are soldiers that are to follow his orders to the letter. Because of this, when Leon is at the reigns, Aichi is sure to have a tough time.
Christopher Lo
An elementary school-age kid, he's attempting to study at the world's top universities, so he's under a ton of stress. While Chris is on a team, he feels very much alone. It's possible that is what caused him to enter the state of mind called PSYQualia.
Leon Soryu
Thoughn he's just a Middle Schooler, he's a boy who follows his own path. He's got a lot on his shoulders, concerning the revival of Aqua Force and returning the Soryu Family name back into one of prestige.
Toshiki Kai (NAL4)
Because Kai has met with Takuto, he knows the stituation, But Kai realizes it'd be pointless for Aichi to meet Takuto relying on his power. Therefore, as long as Aichi doesn't ask, Kai refuses to mention anything willingly.