Annihilargh

The Anihilargenesistoriathimiorgost (Anihilaarg for short) was an extremely powerful and dangerous device used by the ancient Contemelia. It looks like a purple box with a red button inside it. The Anihilaarg had the power to destroy or create an entire universe when activated.

Background
The Anihilaarg was used by the Contemelia as they traveled across the multiverse playing various practical jokes on the inhabitants of a universe. If the Contemelia did not like a particular dimension, they would use the Anihilaarg to reduce it all to nothingness however that was not true.

The Anihilaarg was intended to create a universe as an experiment. It has never been a weapon as believed in childhood tales.

At some point in time, the Contemelia believed to died off, but their vessel still flew across the multiverse labyrinth, as it passed into legends along with its weapon of judgment.

Omniverse
The Anihilaarg first appeared in So Long, and Thanks for All the Smoothies, where the vessel materialized in the universe and appeared above the Earth, Argit was sent aboard the ship by Milleous to obtain the Anihilaarg while the Vreedle Brothers sought it for themselves.

Later in the episode, it was accidentally activated when Ben, Rook, the Incurseans and the Vreedle Brothers were fighting to obtain it. It destroyed the entire universe, but Ben recreated it as Alien X. With the Anihilaarg activated, it's purpose of destroying a universe was complete, and it was rendered useless.

Everyone present (other than Ben) believed that the Anihilaarg was defective, unknowing that the universe was even destroyed in the first place as Rhomboid went over and crushed the Anihilaarg underfoot, destroying it completely.

In Mud is Thicker than Water, it's revealed that Blukic and Driba fixed the Anihilaarg and that it's being kept at Plumber Headquaters with a fake being used as bait.

In Collect This, Ben offers a detailed replica of the Anihilaarg to Collectimus in exchange for the Earth.

In The End of an Era, set years into the future, the Anihilaarg is stolen by Subdora, Exo-Skull, and Maltruant who combines it with energy from the Dwarf Star before fleeing on a Time Beast carriage.

Ben chases after Maltruant in A New Dawn all the way to the beginning of the universe to replace the current one with one in his image by switching the Anihilaarg that was about to be used for the experiment being conducted by the Contemelia that will result in the current universe with his modified one. Taking advantage of the Omnitrix fail-safe that will keep him alive in the event of life-threatening conditions, Ben is able to neutralize and destroy the modified Anihilaarg and replace it with the original creating the universe as intended.

Ben 10: Omniverse

 * So Long, and Thanks for All the Smoothies (first appearance)
 * Mud is Thicker than Water (fake)
 * The End of an Era
 * A New Dawn

Etymology
The first part of the full name is derived from "annihilate", which means to destroy completely. The second part comes from "genesis", which means the origin of something.

Trivia

 * According to Ben in Mud is Thicker than Water, the Anihilaarg is the most dangerous weapon in the universe.
 * All throughout So Long, And Thanks For All The Smoothies, Ben had a hard time pronouncing Anihilaarg, causing everyone else to say it for him. He finally said it right as Alien X.
 * It is said that the Anihilaarg isn't its full name, saying that "Anihilaarg" is all that could be said of its full name before it is activated.
 * This is a reference to "The Castle of Aaargh" from Monty Python and the Holy Grail, as it was believed that it was all that was written by the original writer before he died.
 * Its full name is revealed by the Contemelia in A New Dawn.
 * The Anihilaarg is similar to Marvel Comics' Ultimate Nullifier, owned by Galactus, the Devourer of Worlds. It too has the power to destroy an entire universe.
 * The Anihilaarg is also similar to that of The Genesis Devicefrom Star Trek, as both devices are able to create and end life, depending on the situation. However, The Anihilaarg does not do both as The Genesis Device can.