Legendary Weapons/Weapon Effects

Overview
One of the many ways wielders of Legendary Weapons or Vassal Weapons can power-up is by expanding their collection of weapons. This can be done by either absorbing different materials, copying another weapon of the same type or having it forcibly unlocked by a powerful creature or magic. Each different weapon form provides different bonuses to user's stats or abilities. These bonuses come in two forms: Equip Bonuses and Special Equip Effects. As a short summary, Equip Bonuses can eventually become a passive skill no matter what form the weapon is currently in while a Special Equip Effect is limited to a specific weapon form.

Equip Bonuses
Equip Bonuses are special stats or abilities that are active when its respective weapon form is being used, such as "+1 Defence" and "Air Strike Shield". However, as the weapon form is being used, it levels up and the Equip Bonuses then become. Unlocked Equip Bonuses can be used at any time no matter what weapon form is being equipped. If two weapon forms have the same Equip Bonuses, such as "Poison Resistance Up (Medium)", then upon unlocking one, the other is replaced by a different Equip Bonus, usually a flat stat boost equal to the relative power of the weapon form. Equip Bonuses of different levels, such as (Small) and (Medium), have their effects stack. Known levels of Bonuses are (Small)/(Low), (Medium), and (Large)/(High); it is unknown if there is a difference between (Small) and (Low) or (Large) and (High), or if they just mean the same thing.

Passive Ability Increase

 * Accuracy: increases the user's accuracy.
 * Agility: Increases the user's agility stat.
 * Attack: Increases the user's attack stat.
 * Awareness Boost: Improves the user's awareness
 * Back Defence Boost: Improves the user's defense when struck from behind.
 * Blinding Endurance: Allows the user to resist blinding effects.
 * Curse Attack Resistance: Reduces damage from cursed attacks
 * Cost Reduction: Reduces the cost of certain skills
 * Damage Reduction: Reduces a certain percent of damage from a specific type of enemy.
 * Defense: Increases the user's defense stat.
 * Defense Power: Increases the user's defensive power.
 * Fire Resistance: Increases the user's fire resistance
 * Dragon Magic Disposition Awakened: Unlocked the ability for the user to use Demon Dragon magic.
 * Growth/Maturation Adjustment: Increases the maturation rate of the type of people or creatures specified owned by the user (ex. slaves, monsters, filolials).
 * Growth Stat Adjustment: Increases the growth of the specified creature's abilities as they level and power-up.
 * Light Resistance Boost: Increases the user's resistance to Light attacks.
 * Magic Power-Up: Increases the user's magic power.
 * Night Vision: Allows the user to see and fight better in the dark.
 * Paralysis Resistance: Allows the user to resist the paralysis status effect.
 * Poison Resistance: Increases the user's resistance to poison.
 * Protection of the Dragons: Gives the user the ability to use Way of the Dragon Vein.
 * Sealing Resistance: Resists the user's abilities from being sealed.
 * Sense of Smell Up: Improves the user's sense of smell.
 * Shadow Resistance: Increases the user's resistance to Shadow attacks.
 * Shikigami/Familiar Power-Up: Increases the power of the user's shikigami.
 * Sound Wave Endurance: Allows the user to resist sound attacks.
 * SP Up: Increases the user's skill point (SP) reserves.
 * Spirit Binding Limited Release: Reduces the sealing effects of the Sakura Stones of Destiny upon the weapon. Allows the user to be able to unsuppress 4 of the following: Skills, Magic, Stat Bonuses, Growth Adjustments, Mastery Level, Rarity, Refinement, Spirit Enchants, Status Enchants, Reinforcement, Items Enchants, and Job Level.
 * Spirit Attack Resistance: Allows the user to resist spiritual attacks.
 * Stamina Up: Increases the user's stamina reserves.
 * Stamina Use Down: Reduces the user's consumption of stamina.
 * Status/Power Adjustment: Increases the status of the type of people of creatures specified owned by the user (ex. slaves, monsters, filolials).
 * Strength: Increases the user's physical strength.
 * Support Magic Visual Aid: makes support and debuff magic easier for the user to see.
 * Vision Up: Upgrades the vision skill which gives the user additional information about the environment.
 * Weapon Restoration: Allows the user to repair weapons at the specified quality level.

Active Ability Increase

 * Ability Increase while Carrying: Increases the user's abilities while carrying others.
 * Ability Increase while Riding: Increases the user's abilities while being carried.
 * Absorption Ability: Improves the quality of materials collected.
 * Alert Shield: Sends out an alarm if an enemy came within 20 meters of the user.
 * Compounding: Allows and unlocked compounding recipes within the shield at the specified level or context.
 * Cooking: Unlocks cooking within the shield.
 * Cooking Quality Improvement: Improves the quality of the user's cooking.
 * Dissection Ability: Improves the user's butchering ability.
 * Enhance Power of Combination Skills: Increases the power of combination skills.
 * Enhance Power of Curse Weapons: Increases the power of curse series weapons.
 * Fine Crafting: Improves the quality of the user's crafts.
 * Fishing: Improves the user's fishing ability.
 * Medicine Effective Range Expansion: Expands the range of medicine. If medicine is applied to a single person, people nearby will also be treated as if they received the same medicine.
 * Medicine Efficacy Up: Increases the potency of medicines.
 * Mining: makes it easier for the user to mine.
 * Naval Combat: Increases the user's ability to fight on ships.
 * Plant Analysis: Allows the user to view the characteristics of plants.
 * Plant Appraisal/Classification: Unlocks and improves the ability to appraise plants.
 * Plant Reform: Allows the user to modify the characteristics of plants.
 * Recipe: Unlocks recipes within the shield at the specified level.
 * Reincarnation Recognition: Allows the user to detect the reincarnated.
 * Rickshaw Skill Up: Improves the user's ability to carry others.
 * Sharpening Level: Improves the user's sharpening ability.
 * Swimming: Increases the user's swimming ability.
 * Undersea Battle Ability: Increases the user's ability to fight underwater.

Unknown Abilities

 * Alert Range: Unknown. Unlocked with the Karma Rabbit Familia Shield.
 * Collection Skill: Unknown. Unlocked with the Wood Shield.
 * Inventory Rot Resistance: Unknown. Unlocked with the Inter-Dimensional Zombie Shield.
 * Metalworking: Unknown. Unlocked with the Iron and Copper Ore Shields
 * Beginning of 0: Unknown. Unlocked with the Dragon King Shield 0.
 * Soul Sympathy Enhancement: Unknown. Unlocked with the Wave Sealing Sword
 * Soul Sympathy Maintenance Extension: Unknown. Unlocked with the Wave Sealing Sword

Special Equip Effects
Special equips (or special effects) are bonuses that unique to their respective specific weapon. Unlike equip bonuses, special equip abilities cannot ever be used with different weapon forms.

Unknown

 * Anti-Evil Spirits: Unknown. Unlocked with the Okitsu Kagami: Hetsu Kagami Mirror.
 * Army Roar: Unknown. Unlocked with the Shield of the Beast King III.
 * Blessing of the Sacred Tree: Unknown. Unlocked with the Spirit Tortoise Sacred Tree Shield.
 * Call of Compassion: Unknown. Unlocked with the Shield of Compassion.
 * Demon Dragon's Protection: Unknown. Unlocked with the True Demon Dragon Shield.
 * Dragon Scale: Unknown. Unlocked with the Demon Dragon Shield.
 * Enchant: Unknown. Unlocked with the Shield of Compassion.
 * Growth Power: Unknown. Unlocked with multiple shield including the awakened Spirit Tortoise Shell Shield (Volume 15).
 * Judge of Reason: Unknown. Unlocked with the Shield 0.
 * Magic Sharing: Unknown. Unlocked with the Shield of Wrath III.
 * Pacifier Beast: Unknown. Unlocked with the Sakura Stone of Destiny+ Shield of the Beast King.
 * Power of Devotion/Power of Loyalty: Unknown. Unlocked with the Shield of the Beast King.
 * Power of Trust: Unknown. Unlocked with multiple shield including the Shield of the Beast King II (Volume 21).
 * Primal Dragon: Unknown. Unlocked with the Dragon King Shield 0.
 * Protection of the Ancient Flora: Unknown. Unlocked with the Spirit Tortoise Sacred Tree Shield.
 * Roar: Unknown. Unlocked with the Shield of Rage II.
 * Shield Transparency: Unknown. Unlocked with the Iron Shield Pistol.
 * Spirit Blessing: Unknown. Unlocked with the Sakura Stone of Destiny Shield.
 * Warding: Unknown. Unlocked with the Okitsu Kagami: Hetsu Kagami Mirror.
 * White Tiger Fang: Unknown. Unlocked with the White Tiger Fang Shield.
 * Wild Swing: Unknown. Unlocked with the Iron Sword Shield.
 * World Protector: Unknown. Unlocked with the Shield 0.