Mega Weapon

The Mega Weapon is a tremendously powerful weapon in Ninjago: Masters of Spinjitzu. It was created when Lord Garmadon brought the Golden Weapons to the Golden Peaks.

Darkness Shall Rise
Lord Garmadon used the Golden Weapons' power to recreate the Destiny's Bounty as The Black Bounty. He used the ship to reach the Golden Peaks, where he united the Golden Weapons into the Mega Weapon.

Pirates Vs. Ninja
As the Black Bounty left the Golden Peaks, the Serpentine asked Lord Garmadon about the capabilities of the Mega Weapon. Garmadon did not know, but the discussion was halted when the Ultra Dragon flew by. As the Black Bounty flew in pursuit, Lord Garmadon tried to use the Mega Weapon to harm the Ultra Dragon. To his dismay, nothing happened, but Garmadon covered his impotence by claiming that the Serpentine's poor piloting skills ruined his shot.

Before the Serpentine could question him further, Garmadon retreated to the captain's quarters and angrily wondered why his Mega Weapon failed to activate. In a fit of rage, he struck a nearby desk, opening a secret compartment containing Captain Soto's log. Upon reading it, Lord Garmadon realized that the Pirates were more competent than the Serpentine and wished to have a crew like them. Suddenly, the weapon seemed to react, glowing brightly and draining Lord Garmadon's energy.

As he tried to catch his breath, Lord Garmadon heard unfamiliar voices above the room. Up on deck, the Serpentine were arguing with none other than Captain Soto's crew. While they were arguing over the ownership of the Black Bounty, Lord Garmadon realized what had happened: the Mega Weapon could only create, not destroy, and the strain of its use meant that he could only use it once a day.

Double Trouble
Now knowing the limits of his Mega Weapon, Lord Garmadon consulted his minions on ideas for defeating the Ninja. After several poor suggestions (including recreating the Great Devourer, creating another group of pirates, and making a really big ham sandwich), he used the Mega Weapon to create the Bizarro Ninja to match the power of the real Ninja.

Ninjaball Run
During the Ninjaball Run, Lord Garmadon found himself neck and neck with the Ninja's Ultra Sonic Raider. Desperate to stop them from winning the money they'd need to save Dareth's dojo, he wished for an obstacle that the Ninja could not overcome, and the Mega Weapon created a massive chasm in the Ninja's path. The power drain left Garmadon unable to defend himself when the police caught up with him after the race, but Skales picked him up in the Serpentine Bus.

Child's Play
At the Ninjago Museum of History, Lord Garmadon used the Mega Weapon to resurrect a prehistoric creature known as the Grundle to hunt down the Ninja. The Ninja interfered, delaying the Grundle's resurrection, but also transforming themselves into children.

Wrong Place, Wrong Time
When the Ninja confronted Garmadon in The Lost City of Ouroboros, he attempted to use the Mega Weapon against them, only for the tip to be frozen by Lloyd. Lord Garmadon was forced to flee while his minions fended off the Ninja - infuriated at their continued persistence, he used the Mega Weapon to travel back in time to prevent the Ninja from ever forming and training Lloyd. This failed, however, when the Ninja used the Golden Weapons from the past to combat and destroy the Mega Weapon. The Mega Weapon is seen in the present as a star in the sky by Sensei Wu.

Trivia

 * So far, the Mega Weapon only exists in the cartoon series. However, it appears to be designed with the possibility of being made into an accessory in a future Lego set.
 * Lord Garmadon demonstrates the ability to use the power of Creation with the Golden Weapons, even before he creates the Mega Weapon. However, he only uses it to repair and transform the Destiny's Bounty, so it may be that the separate weapons are only capable of transforming existing objects, instead of creating things on a large scale.
 * The head of the Mega Weapon incorporates details of all four of its component elements; Fire and Lightning on the sides and Earth and Ice in the middle.