- Were you looking for the set?
|“That place is just a salvage yard now.”|
|— Cole about Stiix|
Stiix is a large city built atop the Endless Sea and home to a seaweed creature, amongst other stranger creatures. Stiix would act as a haven for Ninjago's scum and lowlife such as criminals and thieves. However, most of it would end up being destroyed after The Preeminent possessed the entire city in an attempt to devour its inhabitants' souls. The city would later being repaired sometime after the Battle of Stiix.
At some point in time, following Ninjago's creation but preceding The Overlord's defeat and the end of the Stone Wars, the City of Stiix was built along the coast, becoming a popular destination for criminals such as the Sky Pirates.
Clancee, a young aspiring Serpentine pirate, eventually landed a job at Stiix swabbing the docks. Later, the Misfortune's Keep docked at Stiix, looking to recruit more aspiring pirates as part of its crew, attracting a regular human and Clancee. As the Misfortune's Keep left Stiix, Clancee was chosen amongst the two and assigned to the crew by Flintlocke.
While fleeing the authorities, Doubloon would be directed by a passing Chokun to Stiix. There, he would stumble across Flintlocke and Clancee and attempt to steal Nadakhan's treasure, only to be caught red-handed and transformed as a result.
Later, at an unknown point in time, the Teapot of Tyrahn, with the trapped Nadakhan inside, ended up in Stiix under unknown circumstances. Several years later, Ronin would also set up a pawn shop at Stiix, filling his store with countless stolen goods, such as Jacob's stolen guitar, the Blade Cup, a Jadeblade, and so forth.
In an attempt to get the Scroll of Airjitzu, the Ninja negotiate with Ronin over its price, and are eventually forced to find work in expanding Stiix by building more bridges further out into the water. However, after a fly messed up Zane's voice box, their attempts to expand the city would be reversed and subsequently halted. Later, chaos would ensue when Morro and the Ghost Warriors, Ronin, and the Ninja all fought over the Scroll of Airjitzu.
After escaping the Ninja with the Sword of Sanctuary in tow, Ronin would arrive back at Stiix and enter his pawnshop, which had been taken over by Morro, Soul Archer, Bansha, and Ghoultar. However, Ronin would only be swindled and forced to keep serving the Ghost Warriors, and after being possessed in order to send a fake message to the Ninja, would promptly leave the city.
The inhabitants of Stiix would go on to celebrate a festival until Morro unleashed waves of Ghosts and Skreemers from the Cursed Realm using the Realm Crystal. The city would fall under Morro's command, only for the Ninja to clash with him in an attempt to rescue the citizens and stop The Preeminent's arrival. In the process, Ronin's pawnshop would be destroyed; Morro succeeded in bringing his master to Ninjago and banished Lloyd to the Cursed Realm.
As a result of The Preeminent's arrival, the Ninja attempted to kill the massive ghost by destroying the foundations of Stiix with their Aeroblades in order to drop her into the Endless Sea below. To protect his master, Morro rallied the Ghosts to help The Preeminent possess the entire city of Stiix. Transforming the city into a massive form armed with multiple arms and legs, The Preeminent chased the fleeing residents of Stiix in order to devour their souls. However, when Nya unlocked her True Potential, she knocked the Preeminent into Hallows Trench, killing the ghost and resulting in the destruction of Stiix.
The remains of the destroyed Stiix would be salvaged by its inhabitants in their attempts for repairs. In the process, Clouse, searching the wreckage, managed to recover the Teapot of Tyrahn and free Nadakhan, only to be tricked into wishing himself inside the Teapot. Later, the Ninja would arrive there in order to find Clouse, only for the citizens to be noted by the news of the Ninjas' supposed crimes. Stiix's vengeful inhabitants, blaming the Ninja for the destruction of their city, proceeded to chase them across the remains of the city, accidentally wrecking it even more in the process. When the Destiny's Bounty arrived at the remains of Stiix, it was captured and brought down by the police.
As a result of Jay's final wish erasing the events of the season, the damage the inhabitants accidentally caused Stiix's remnants were reversed, alongside several of their repairs. Likewise, Clouse, having had his memories of the events erased, was placed back there alongside the Teapot of Tyrahn, only to be driven off by the angry citizens. At the same time, several screens across the rebuilding Stiix also broadcasted Jay and Nya's reconciliation.
- The name of the city appears to be based on the river Styx from Greek mythology. In Greek myth the River Styx borders the Underworld and living worlds. It is also known as the "River of Hate."
- It is often called the "city on water."
- According to "Curseworld, Part II," Stiix is a county.
- Unlike Ninjago, Stiix detests the ninja for their indirect role in its destruction.