Following the defeat of The Preeminent, the Ninja rose in popularity and began being treated as celebrities. Kai in particular loved the attention. Following the discovery that Clouse had managed to escape the Cursed Realm, Kai and the other Ninja headed to Stiix to stop him, taking a brief detour to the hospital for Lil' Nelson's Grant-a-Wish. Upon arriving in Stiix, the ninja were unable to locate Clouse and discovered to their horror that they had been framed for a crime free. Now wanted criminals, Kai and the other Ninja were forced to split up to avoid detection.
After a brief meeting with the other Ninja where they discovered that a Djinn might be behind their framing, Nya and Kai headed to Jamanakai Village where Nya had hid spare bikes. Upon receiving a distress call from Zane, the two headed to the Corridor of Elders, only to be ambushed and captured by Ronin, who had been paid to round up the wanted Ninja. Once all six of them had been captured, they were lead onto a bus bound for Kryptarium Prison.
While at Kryptarium, Kai and the other Ninja learned from Captain Soto that this Djinn was none other than Nadakhan, a feared pirate captain whom Soto had trapped himself centuries ago. That night, as part of Lloyd's prison break plan, Kai found Soto and freed him from his cell in exchange for information on how to defeat the Djinn.
While Cole and Lloyd tried to find the Misfortune's Keep, Kai and Zane were assigned to recover the Destiny's Bounty 2.0. However, after being attacked by the guard and his dog, the two of them were forced to flee.
Later, after regrouping with the other Ninja at Yang Tavern, they learned of Misfortune's Keep attack on Ninjago City and decided to come out of hiding to defend the innocent and retrieve Soto's Lantern. During the battle, Kai and Jay were separated by an explosive barrel thrown by Monkey Wretch. Before Jay could catch up, Nadakhan transported the Red Ninja to Cannon Beach to trick him into using his three wishes.
In an attempt to escape, Kai wished to go back, only to be taken back in time to when his father was a humble blacksmith. After witnessing his father ask for his help, Kai, not wanting to mess with the timeline, demanded that Nadakhan return him back to a time when the latter wasn't present, when his fan girls still appreciated him, etc. Because of the high content of his wish, Nadakhan instead chose to focus on a single aspect, transporting Kai into an alternate reality where all of the psychotic fan girls began chasing him around. In desperation, the Red Ninja was goaded into wishing it all away, resulting in his imprisonment in the Djinn Blade. As a result, Nadakhan would use the power of his soul to begin tearing chunks out of Ninjago.
Whilst trapped inside the Sword of Souls, Kai would be freed by Jay alongside the rest of his imprisoned allies, their release resulting in the defeat of several Sky Pirates converging on their position.
After thanking the members of Jay's new team, Kai went with the other Ninja to stop Nadakhan from marrying Nya. However, they failed to stop the ceremony and retreated before Nadakhan could capture them. Regrouping on the Misfortune's Keep with the now reformed Dogshank and Flintlocke, they discovered from Jay not only where Clancee kept the Tiger Widow Venom but also the true reason behind the wishes Nadakhan granted: their inabilities was only interpretation on Nadakhan's part: in the end, Nadakhan's powers were limited in that he had to solely rely on his victims to accomplish his wishes, as the ability came from its rightful owner. With this, Flintlocke regained his aim and was declared the one to shoot Nadakhan with the venom while the others distract the Djinn.
The Ninja put the plan into action, though discover Nya has been possessed by the now-revived Dilara. Although they evade most of the attacks, Nadakhan turns them into gold statues until only Jay is left. Flintlocke is soon able to take the shot, successfully hitting Nadakhan and his power begins to diminish: unfortunately, the venom also hit Nya, who soon dies in Jay's arms. Everyone is devastated, Kai having to be comforted by Zane while the weakened Nadakhan musters up his remaining strength, though it's in vain as Jay wishes from the heart that Nya had taken his hand and that Nadakhan was never freed. Time soon reverses to when the ninja are on the roof of Ninjago City hospital with only Jay and Nya remembering all of the events. The two renew their relationship, which everyone is happy for, though Kai becomes disgusted from seeing his sister kiss Jay.