Vearth Weapon

Arms of Vearth (大地武器 Vāsubuki) are pieces of ancient technology created by the original Birkans. Forged millennia ago, the pieces of vearth were everyday pieces of technology that allowed the Birkans to thrive during a time when Earth was populated with dangerous mythical beings. After the Birkan's extinction, these relics lost their power and were scattered throughout the world. After Tsubasa's death, the Birkan Ghosts reactivated the power of these weapons so their souls could remain in the physical plane. In the present day, these items have been dubbed Vearth Weapons, and have become legendary armaments that provide their users with great mystical power.

History
Millions of years ago when the Birkans were the world's dominant race, the planet was known as "Vearth". Vearth was populated by mystical beings that constantly threatened the Birkans. In order to survive and ultimately thrive, the Birkans invented incredible pieces of technology that manifested the dormant supernatural powers of Birkans.

After the Birkan's near extinction, each item's power was sealed away and scattered throughout the world, eventually lost with time. When the Birkans resurfaced many millennia later, they named these relics the "Arms of Vearth", as they were the only things left from their original home. Surviving Birkans used their power to unseal the arms. For every artifact, a piece of a Birkan's soul existed within it. Tsubasa, the last remaining Birkan with a physical body, figured out a way to magnify these souls enough to revive Birkans. To augment the remnants of any lost Birkan's soul, these weapons must be wielded by someone with a strong spirit. That person's Haki amplifies the Birkan soul enough to return the Birkan to life, albeit in the form of a ghost.

In the current age, these pieces of Vearth have be dubbed "Vearth Weapons". Their origins are unknown to most, and they are seen as mystical weapons that can give someone the power to combat even those empowered with Devil Fruit abilities.

Abilities
The Vearth Weapons draw their power from the user's Haki, but their abilities are based on whatever Birkan created it. Every takes a different from, but any number of Vearth Weapons could've been created by a single Birkan. This means that if two people possess pieces of Vearth created by the same Birkan, their powers will be similar. For example, the electro-kinetic Apollyon created Thunderclap, Twin Snakes and Flash armor. While these weapons are completely different, their abilities all revolve around lightning.

Certain Vearth Weapons are said to be too powerful to be used by a human, and appear in a sealed form rather than allowing the user to use the full extent of their power. These pieces of Vearth are called Extreme Vearths. Their true power is sealed away until the ghost of the original creator unlocks it. After the initial unsealing, the user can seal and unseal the Vearth Weapon at will. In their unsealed form, the Vearth Weapon's power increases ten fold. King Nefertari's Thunderclap is an example of an Extreme Vearth.

Azazel was capable of manufacturing psuedo versions of these items by using the powers of synthetically created Birkans as a base. Other than Macbeth himself, the members of the Macbeth pirates possess these types of Vearth Weapons. These pseudo arms require their source being to alive in order to use its abilities. Rango's unnamed bubble cannon drew it's power from Egyn, and when Egyn was destroyed he lost his ability to create bubbles.