A storm is brewing over Knighton. Monstrox has taken the form of a cloud and is raising an army of lightning infused Stone Monsters. His first target is the new Lavalands Amusement Park.

The Cloud of Monstrox is growing more and more powerful with every Forbidden Power Jestro inserts. The capitol of Knighton is under attack. The Fortrex is damaged and Clay is turned to stone. Dark clouds are truly gathering over the realm.

At K.O.M.A. (Knightonia Official Museum of Art) Monstrox learns that a Forbidden Power tablet is hidden, and he will do anything to get it. Especially if King Halbert is happens to visit at the same time. The NEXO KNIGHTS must save all!

Forbidden Power missions are spawned on the map by the zap of Monstrox. See what happens when the knights take on Cosmic. Before starting the mission try out different Combo NEXO Powers to find the perfect one that can counter these Cosmic attacks.

In a massive chase around Knighton, the NEXO KNIGHTS attempt to keep the Book of Betrayal out of the Book of Monster’s grip. But the evil book is persistent. Will he get the final piece of his evil puzzle?

Never fear – Aaron is here! For this battle, Aaron is charging up and using The Sword of Merlok to help him beat these monsters! This Merlok Power creates a giant sword that falls and lands in the middle of the battlefield, causing huge cracks in the ground that deal area-of-effect damage to all enemies. Additionally, golden eggs fall from the sky, crushing enemies beneath them.

Macy is mad! The three Harpies have kidnapped her mom Queen Halbert. The NEXO KNIGHTS use everything in their power to rescue her. But is kidnapping the real plan or is the Cloud of Monstrox after something else?

When Jestro the Jester finds the Book of Monsters, chaos breaks loose in the Kingdom of Knighton. Can the newly graduated Knights from the Knights’ Academy save the kingdom?

Rival to the King, Jorah Tightwad thinks his knights – the Tighty Knighties – are easily better than the NEXO KNIGHTS, so he challenges King Halbert to prove who’s better during the King’s Birthday Tournament.

The Book of Monsters catching a cold means trouble for the NEXO KNIGHTS when he can create an entirely new kind of “snotty” monster.