The user can create or wield weaponry with power over apocalyptic forces, which grants the user a wide variety of apocalypse-based abilities. This ability is not only specific to mystic weapons, but also technologically advanced weapons. The power of the weapons depends on what they were created for or what level of apocalypse-based ability they possess.
Weapon may require a source of power such as an item.
an apocalyptic event may not wipe out all life, it merely has to cause a collapse of most society on a planet / realm - it is possible for new civilizations to return to these realms after the apocalyptic event (unless the world or realm is completely erased).
advanced use of time-travel, reality-alteration or other nigh-omnipotent powers can undo an apocalyptic event and may even render such items useless (or in the case of exceptionally potent cases erase knowledge of the weapon entirely, meaning it can never be used in the first place).
Species 8472 (Star Trek)
Imperium of Man (Warhammer 40,000)
Crypto (Destroy All Humans)
Armageddon Blade (Darksiders)
Doomsday Machine (Star Trek)
Nuclear Weaponry (real world)
Starkiller Base (Star Wars)
Death Star (I & II) (Star Wars)
Sun Crusher (Stars Wars Legends)
Centerpoint Station (Stars Wars Legends)
Eclipse-class Dreadnought (Stars Wars Legends)
Eye of Palpatine (Stars Wars Legends)
Galaxy Gun (Stars Wars Legends)
Interplanetary Ion Cannon (Stars Wars Legends)
Furon Saucer (Destroy All Humans)
Quantum Deconstructor (Destroy All Humans)
Doomsday Machine (Star Trek) had the power to destroy entire worlds.
Species 8472 (Star Trek) had access to ships capable of completely destroying planets.
Known to the Killiks as Qolaraloq or the World Puller, Centerpoint Station (Star Wars Legends) was capable of moving entire planets with its tractor beams.
A class of Imperial Super Star Destroyer manufactured by Kuat Drive Yards, the Eclipse-class dreadnought (Star Wars Legends) carried an axial superlaser, similar to but significantly less powerful than one of the component beams used in the Death Star's superlaser.
Constructed at the behest of Emperor Palpatine during the second year of the Galactic Empire, the Eye of Palpatine (Stars Wars Legends) was a colossal, asteroid-shaped super dreadnaught.
Commissioned by the "reborn" Emperor Palpatine, The Galaxy Gun, or Galaxy Weapon (Stars Wars Legends) was a superweapon capable of firing large, destructive projectiles equipped with particle disintegrator warheads capable of destroying an entire planet.
The Sun Crusher (Stars Wars Legends)
The Imperium (Warhammer 40,000) can authorize use of Exterminatus weaponry, which can erase all life on a planet.
Nuclear Weaponry is among the most powerful and destructive known weapons humanity has ever created, capable of ending current civilization if used in full-scale war.
the Tsar Bomba was the most powerful nuclear weapon in history, making it apocalyptic even among an already society-ending arsenal of weapons.
Furon Saucers (Destroy All Humans) have an immense amount of power, capable of destroying cities..
..which is taken to even greater extremes with the Quantum Deconstructor, which will wipe out anything in its range.