The Stone Army

As the Serpentine battle in the City of Ouroboros, Garmadon arrives with his master plan; he has remembered the 'Island of Darkness' mentioned in Captain Soto's logs and plans to find it, and use its power for himself. While they are at sea, the Serpentine Generals betray him, throwing him from their Rattlecopter into the sea, and Skales is declared their leader. Meanwhile, the Ninja are called to the Museum of History to confront a strange force; venom from the Great Devourer has leaked into the sewers and brought a mass of tiny stone warriors to life. The Ninja easily defeat them, then meet up with Sensei Wu and Misako, who is revealed to be Lloyd's mother. Lloyd, bitter about Misako apparently abandoning him, finds out that his mother has been trying to find a way of restoring the balance without endangering either Lloyd or Garmadon. To this end, she reveals the full story of Ninjago; in the beginning, there was the First Spinjitzu Master, but against him was pitted a being called the Overlord, the first and greatest dark power. The Overlord created the Stone Warriors to aid him in battle, and, to prevent good losing the battle, the First Spinjitzu Master split the land he had created in two, with the Overlord trapped on the dark half of Ninjago, which vanished. Even as Misako is explaining, the venom of the Devourer brings a huge, four-armed stone warrior to life. It immediately goes on the rampage and pursues the Ninja through the museum. Thankfully, they coordinate and trick the Stone Warrior into toppling down the bottomless pit where he was found. After this, Misako joines the group. Meanwhile, Garmadon washes up on an unknown tropical island and is guided by an unseen force to a stone monument atop the island, with four levers perfectly suited for him. He turns them, and the other half of Ninjago, corrupted by the Overlord's shadow, rises around him.

Note: First appearance of Misako, the Stone Army, and the Overlord.