This is my own opinion based on their personalities in the show.

Kai: Gryffindor
The main traits a Gryffindor values are courage, bravery, nerve, and chivalry. We see Kai in the very first episode trying to keep the family shop going, and when Nya gets captured he does everything to save her, even tolerate Jay. As the series continues we see him become a prime example of a Gryffindor.

Jay: Ravenclaw
He said it himself he's an inventor, a poet, and so many other things. He may not be the brightest of the group but he strives for knowledge, Ravenclaw would be perfect for him.

Cole: Gryffindor
He lied to his father because it made him proud of Cole. Cole values his family's happyness, he has kept his promise to his mom. He values bravery but also humbleness. Cole could also be in Hufflepuff but Gryffindor would be better for him.

Zane: Slytherin
I originally thought he would be a Ravenclaw cause robot, but then I remembered his chess match against Nadakahn. This man had taken all the information on Nadakahn and immediately knew what his first and second wish was. He is cunning, resourceful and would excel in Slytherin.

Nya: Slytherin
She is for sure a Slytherin, Nya made a name for herself through Samurai X, she knows she is the most important member of the team, she can be a bit prideful because of this, but her determination makes up for this.

Lloyd: Hufflepuff
He is loyal to the team, very trusting, which can be a weakness as shown by Harumi but it's his best trait, seeing the best in people.

Pixal: Hufflepuff
Hufflepuffs value hard work, patience, justice, and loyalty, which fits Pixal to a t.

Skylor: Slytherin
Skylor would thrive in the Slytherin house, she has leader potential, is very resourceful in tight situations, and is very cunning. She could also be a Gryffindor but Slytherin would be better for her.

Comment what you guys think their houses would be, I'd love to hear if we have the same or different opinions.