Kai

Kai is the Ninja of Fire, and has a little sister named Nya, who is also the mysterious Samurai X. His two vehicles are the Destinys Bounty and the Kai Cycle. He is the protector of the Green Ninja, and was the last ninja recruited by by Sensei Wu. He is the only ninja known to have a sibling, and was the final ninja to reach his full potential.

Background
Kai, along with his sister, were the children of the blacksmith and owner of Four Weapons. When their father died, Kai took it upon himself to keep the family business going and swore he would become an even better blacksmith than his father.

Description
There is eight different minifigures of Kai. DX, ZX, regular, Kendo, NRG, Kid version, casual, and blacksmith. In all of them, he's wearing his red ninja suit, a hoodie, a apron, or a shirt and jacket.