Across the series, key milestones fundamentally reshape the realm:
- Season 1 (Rise of the Snakes): Young Lloyd releases the serpentine tribes, but the prophecy reveals that he—not Kai—is the destined Green Ninja who must fight his father. Zane discovers he is a robot built by Dr. Julien.
- Season 2 (Legacy of the Green Ninja): Lloyd is rapidly aged by Tomorrow's Tea. He achieves the Golden Dragon power, defeats the primordial Overlord, and restores Garmadon to a purified, non-venomous human form.
- Season 3 (Rebooted): The Overlord returns as a digital entity and claims the Golden Power. Zane sacrifices his life in a thermal overload explosion, destroying the Golden Master.
- Season 4 (Tournament of Elements): The ninja discover Zane is alive on Master Chen's island. To defeat Chen's faux-Anacondrai cult, Garmadon banishes himself to the Cursed Realm.
- Season 5 (Possession): Morro possesses Lloyd to unleash the Preeminent. Nya unlocks her true potential as the Master of Water, drowning the realm.
- Seasons 8–9 (Sons of Garmadon / Hunted): Princess Harumi ("The Quiet One") resurrects Garmadon in an evil Oni form devoid of human love. The ninja are defeated; Lloyd loses his powers while the team is exiled to the First Realm, fighting their way back to reclaim Ninjago.
- Season 10 (March of the Oni): The Oni invade through the Realm Crystal. The ninja and Garmadon use the Golden Weapons to perform the Tornado of Creation, saving the world and entering the First Spinjitzu Master's realm.
- Season 14 (Seabound): Prince Kalmaar awakens Wojira. Nya performs a permanent elemental merger with the ocean, saving the world at the price of her humanity and memory.
- Season 15 (Crystalized - Finale): The Overlord returns as the Crystal King, gathering past villains. The ninja restore Nya to human form, reforge their powers into a four-headed Golden Dragon form, defeat the Overlord permanently, and unite the entire world to rebuild their monastery together.