Kai Smith

Fittingly for his elemental affinity, Kai is very hot-headed, prone to taking action before he thinks things through. He is capable of making careful observations when the need arises, but his emotions often override his caution. His single-mindedness made interaction with his teammates difficult at first (especially due to his worry about Nya), but he eventually learned to work with the other ninja. He can be very cocky at times, especially earlier in his career as a ninja, sometimes even to the point of selfishness, insisting that he is better than others, gloating about his victory, or yelling about his failures. He seems to have a large ego as he wanted to be the Green Ninja and lead the team. He eventually grew out of this for the most part, though he occasionally lapses back into a similar mindset. But those emotions are also when his strength is greatest, especially when protecting those he cares about. Kai's personality represents caution, growth, safety, and warmth. He may not say it much, but he deeply cares about his loved ones and will do anything to protect them, even if he must sacrifice himself, which is why he's so overconfident.

Later, following the ninja's fame, Kai would end up getting something of a larger head and bigger ego, constantly flirting with girls and enjoying the merchandise styled after him. He indulged in his fame the most out of all of the ninja.[16] Usually, because he often feels insecure, Kai feels like he's useless or insignificant at times or not as good as the other ninja.

Kai also has something of an overconfident stubborn side, believing that he is in the right until overwhelming evidence to the contrary is presented. This is especially pronounced during Lord Garmadon's stay on the Destiny's Bounty; Kai repeatedly accused the four-armed villain of treachery or plotting despite Garmadon's insistence that saving Lloyd was his primary concern at the time.[17] On the other hand, Kai's stubborn streak lends him incredible determination that allows him to bolster the team's spirit in the face of impossible odds.

Despite having no powers at the time, Kai showed intense loyalty through his determination to protect Lloyd when the latter was possessed by Morro.[18] As time passed, Kai mentally connected his power with his self-worth to a greater degree, at one point hesitating to give up his power to save Lloyd and, at another point, losing hope when his power was taken by Aspheera.[19][20][21] However, his desire to protect his friends was able to overcome all this insecurities and allow Kai to see his self-value besides his power, allowing him to become an even better person and ninja.

Overall, Kai is a tough, brave, confident, passionate and also protective ninja. The most prevalent facet of Kai's personality is his good heart and dedication to the people he cares about—if someone can earn his friendship, he will stop at nothing to protect them. Much of his stubbornness and recklessness is due to his desire to help his loved ones, either directly or by becoming strong enough to defeat anyone who might threaten them with their plans. In turn, his friends and family work to balance out Kai's more extreme traits, causing him to become a level-headed mentor for Lloyd by the time he and his comrades begin training the Green Ninja. According to Zane, Kai's desire to protect his friends is just as powerful as his temper.

Unlike his sister, Kai likes to spend time with his parents and doesn't mind when his mother tends to baby him, which he likes. He also formed a better relationship with Ray while playing video games at the monastery with Cole.[12]

After the Merge and finding himself in the Land of Monsters, alone, Kai struggled to keep himself hopeful as he navigated for weeks fighting for survival and trying not to lose his humanity in the process. However, despite all the adversities he faced, Kai remained firm on his convictions, even inspiring a fire dragon driven by vengeance against a monster that killed her child to not kill its own unhatched egg and giving a sentient Fire Mech called Rusty, whose master had turned into a monster, a new purpose. However, as he grew tired, Kai eventually reached his limit, as he almost drowns due to a Sea Monster after it lured him with visions of his friends, sister, and master. But after Rusty sacrificed himself to save him, Kai was able to regain his hope and continue his journey to return to Ninjago. Even after years since escaping the Land of Monsters, Kai is showed to still struggling with what he experienced there, not even disclosing the details with the other Ninja, with the exception of Wyldfyre and only because she accidently found out about it and he knew she wouldn't stop pestering him until he told her all about it.

A few years after the Merge, he is showed to have matured quite a lot, finding the perfect balance to his cocky and impulsive personality. While still vain and loving to brag about his skills, Kai has showed a lot more modesty than he used to. Also, despite still being hot-headed and rush into battle, he is now able to focus on the mission and to sort out priorities. This is especially showed when Nokt attacks Imperium to take the souls of the inhabitants, where Kai remained focused in finding a way to better fight the ghosts, even advising Cole, who was engulfed in anger and grief due to Nokt taking the souls of Bonzle, Fritz and Spitz, to not let his emotions cloud his judgment. One factor that contributed to this was becoming Wyldfyre's mentor, which not only gave him someone with whom he could relate, but it also gave him someone he could guide. Through Wyldfyre, Kai's teaching skills that he had developed while teaching Lloyd were able to fully blossom, as not only he was able to teach her how to properly use her elemental power, but also taught her how to calm down her own temper.

After you died by one of the snake generals during Acronix and Krux. Kai went dull for a long while. Then just as he recovers the merge happens. 5 years after the merge he finally meets all his friends again. Then you..