|LEGO → System → Ninjago|
In "Corruption", the castle is revealed to have originally belonged to King Grimfax, whom Vex attempted to deceive into attacking the Formlings. After causing Zane to develop amnesia and convincing him that he was the Ice Emperor, Vex returned to the castle with him. Zane's powers proved too much for Grimfax's men, who were turned into mindless minions of their new monarch. Grimfax was thus forced to submit to the usurper, and his fortress became the Ice Castle, center of the Ice Emperor's growing domain. Zane eventually created the ice dragon Boreal using his powers, and unleashed it against those who opposed his authority, such as the Formlings, as seen in "The Last of the Formlings."
In "The Never-Realm", the Ninja arrive in the Never-Realm some decades later, and learn from Sorla that Zane is located at the Ice Emperor's Castle. At the castle, Vex learns of their arrival through a shard of dark ice, and advises the emperor to send their Blizzard Samurai warriors to attack the Great Lake village. In "An Unlikely Ally", Lloyd sets out for the castle by the way of the pass known as Wojira's Wrath. Vex attempts to convince Kataru, a prisoner of the castle, to submit to the Emperor, but is refused.
In "Secret of the Wolf", Grimfax returns to the castle and is reprimanded for his failed attack on Great Lake, at which point Vex suggests sending Boreal to finish the job. Going to the top of the castle, the Ice Emperor summons the beast. In "My Enemy, My Friend", Boreal's attack on Great Lake prompts the other Ninja to set out to attack the Castle. On its way back, Boreal stumbles across Lloyd's mech, defeats it, and captures him, bringing him back to the castle where he discovers what Zane has become. In "A Fragile Hope", Lloyd attempts to reason with Zane, but is thrown in the dungeon, where he meets Kataru; the two are later released by Grimfax, who joins their side.
In "Once and for All", Akita reaches the castle and begins making her way to the throne room, unaware that her brother and Lloyd are doing the same. Lloyd's party is ambushed by Vex and the Blizzard Samurai, and Lloyd breaks away to confront Zane. He breaks into the throne room just as Akita is attempting to kill Zane, and a scuffle breaks out between the three in "Awakenings". Zane eventually overpowers his attackers, but Vex rekindles his memories of who he really is, and he reverses the effects of his dark powers. Grimfax thus reclaims the castle with his freed men, and Vex is banished.
- Akita is exclusive to this set.
- Lloyd also appears with a shoulder pad in 70671 Lloyd's Journey (as well as a hair piece and mask) and 70676 Lloyd's Titan Mech (with a different hood). Cole is identical to his release in 70672 Cole's Dirt Bike, and comes with a different hood in 70675 Katana 4X4. General Vex also appears in 70673 Shuricopter, and he and the Blizzard Archer and Swordmaster also appear together in 70676 Lloyd's Titan Mech. The Ice Emperor was later released with Issue #61 of LEGO Ninjago Magazine.