Legendary Weapons

The Legendary Weapons (伝説武器 Densetsu Buki) are summoned and wielded by the Four Legendary Heroes from another world. They are also refereed to as the Four Heavenly Weapons (聖武器 Seibuki), since many religions formed centering around the Legendary Heroes.

Legends
The only known method to obtain a Legendary Weapon is through being summoned from another world. Once the owners of an Legendary Weapon is deceased, their Legendary Weapon will disappear in wait to be summoned again with a new hero.

In order to summon a new hero with a Legendary Weapon, all the current Legendary Hero must die. When a Legendary Hero dies the waves are said to grow stronger each time one dies.

Legendary Weapons specialize in protecting the world they resign in.

Origins
The origins of the Legendary Weapons are still unknown. It is speculated that the Vassal Weapons have a deep tie with the Legendary Weapons and the origins of the world.

By-pass
Legendary Heroes and Vassal Wielders do not require nor can they class-ups when they reach a certain level. Legendary Heroes and Vassal Wielders are also immune to curse slaves seals.

Restrictions
Legendary Weapons repel each other by nature. When the Legendary Weapons are near each other they will cancel experience gain of the other.

Legendary Weapons also restrict users from equipping any weapons asides from their designated weapons.

Translate
Legendary Weapons and Vassal Weapons automatically translate any language they hear verbally to the owners most first language, and also works the other way around for the owner's voice. However this does not apply to written languages such as words and symbols written on paper.

Vassal Weapons have shown the ability to grant companions the ability to translate their voice and to translate what they are hearing. It is unknown whether or not the Legendary Weapons has the ability.

Absorption
Legendary Weapons and Vassal Weapons have the ability to absorb monster loot, materials and items. Absorbing them will allow the weapon to unlock new variations of themselves.

Weapon transformation
Legendary Weapons and Vassal Weapons have the ability to transform into shapes, form and variations through Absorption of different materials. These different variations will give the user when equipped new equip bonuses, which will grant them new stats, skills and abilities.

Passive abilities
Legendary Weapons and Vassal Weapons have the ability to master the new variations of their weapon. When mastered they will keep the equip bonuses effect even if they change to a different variations.

Weapon Copy
Legendary Weapons and Vassal Weapons have the ability to copy different variations of the same weapon.

Strengthening Method
Legendary Weapons and Vassal Weapons all each have unique strengthening methods which can be shared with both the Legendary Heroes and Vassal Wielders.

The strengthening method won't work or appear if the user doesn't truly believe in the strengthening method.

Curse Series
The Curse Series is shown to be exclusive to the Legendary Weapons. It is unknown whether Vassal Weapons have the ability to unlock Curse Series. They respond to the user's strong and negative emotions to create powerful abilities. When going through negative and horrible experiences, the owner will unlock one or several Curse Series depending on how bad the experience is.

The names of the Curse Series is based off the Seven Deadly Sins. They can grants powerful effect and stats bonuses for the Legendary Heroes but they cause a Curse effect to anyone around them and puts a heavy strain on the user.

Legendary Weapons List
Naofumi's Summoned World

Kizuna's Summoned World