Sacred Gear

Sacred Gears, also known as God's Artifacts, are items with powerful abilities bestowed upon humans by the original God from the Bible. They are one of the main points of interest in the High School DxD series.

Summary
The original God of the Bible created the Sacred Gears as part of His system to enact miracles on Earth. It has been stated that certain individuals with Sacred Gears have grown to become very powerful and influential and that a large number of the people who have had their names etched into history, were most likely Sacred Gear possessors. There can be more than one Sacred Gear of the same type such as Blade Blacksmith. Sacred Gears can vary from the common Twice Critical, to the rare Sacred Gear Twilight Healing, with the only exception being the Longinus, which are all unique in their own way. If a Sacred Gear is removed from the owner, they would die.

Only humans or human hybrids can be born with Sacred Gears. Angels and Devils can obtain them by resurrecting a human or human hybrid as one of their own. The Fallen Angels have devised a ceremony to extract and possess a Sacred Gear from the original user.

It is possible for an individual to own more than one Sacred Gear at a time. As to why Angels and Devils are never born with them, yet keep them when transformed from humans, is another mystery. Presumably because God never foresaw the new systems of reincarnating Devils and Angels which arose after His death.

Abilities
Sacred Gears can have a variety of effects, such as Asia's Twilight Healing granting near-instantaneous healing and Siegfried's Twice Critical doubles the power of the user. Yuuto's Sword Birth, for example, can create Demon Swords imbued with different attributes, examples include creating a sword that absorbs holy energy, a sword that devours flame, and a sword that absorbs wind.

"—Desire. Sacred Gears are driven with the power of desire. And it also determines the power for it as well. Even though you are a Devil, your will to desire hasn’t been lost. The stronger you desire, the stronger your Sacred Gear will respond to you."

- Rias Gremory commenting on the abilities of Sacred Gears.

Sacred Gears can also adapt and evolve based on their wielder's thoughts, needs, and feelings, gaining abilities or qualities as time passes. This is stated to be the source of Balance Breaker, and suggested to be the source of the transformation into a Sub-Species.

Balance Breaker
Sacred Gears have an ultimate state of activation called the Balance Breaker, which is the most powerful manifestation of the Sacred Gear. Once reached, the Balance Breaker can be entered again far more easily than the first time. An incomplete Balance Breaker can be reached by self-sacrifice on the part of the user, such as when Issei sacrificed his left arm, allowing it to be transformed into a Dragon arm. However, this sacrifice method does not count as a true activation of Balance Breaker. Reaching the Balance Breaker can be triggered by the feelings of its possessor. Balance Breaker is said to be have been never intended, and that it was a flaw in the system created by God.

Juggernaut Drive
Juggernaut Drive is a special ability exclusive only to the Longinus Boosted Gear and Divine Dividing, and is considered to be a forbidden move. The Juggernaut Drive temporarily removes the seal placed on the Heavenly Dragons, and for users that possess insufficient power the Juggernaut Drive will drain the user's life force which is needed to fuel the power, and drive them insane in the process as they cannot handle it.

For other Sacred Gears that have creatures sealed inside (such as the Regulus Nemea), their Juggernaut Drive goes under a different name called "Breakdown the Beast".

The True Longinus has a similar power as well, which unleashes the 'Dying Will' of the God of the Bible called Truth Idea.

Longinus
Aside from the normal Sacred Gears, there are the Longinus. Longinus are unique top-tier Sacred Gears, each having multiple abilities compared to a normal Sacred Gear which only has one, and has the power to slay Gods. This class of Sacred Gears are also known as the tools that destroy God. There are 13 Longinus in total. However, Azazel has stated that there is the potential for more Sacred Gear to eventually evolve into Longinus, under the right conditions. Also, that Longinus and Balance Breakers were never intended, and are glitches in the system. The Longinus class of Sacred Gears are named for the first Sacred Gear to achieve this level of power, the True Longinus.

Artificial Sacred Gears
It is possible for artificial Sacred Gears to be created. Azazel, the leader of the Fallen Angels and Grigori, has conducted countless research studies on Sacred Gears. He eventually managed to create his own Sacred Gear, the Down Fall Dragon Spear, using the jewel that has Fafnir, one of the five Dragon Kings sealed inside it. Artificial Sacred Gears, however, are inferior to the real ones.

Sub-Species
Sub-Species are Sacred Gears that have taken on a unique characteristic because of the thoughts and feelings of the wielder. They are more powerful than the normal form of the same Sacred Gear, and will sometimes gain a new ability as well. Sometimes, both the Sacred Gear in its normal state, as well as the Balance Breaker will be a Sub-Species, Siegfried's for example, but other times, only the Balance Breaker will be a Sub-Species, such as Yuuto's Blade Blacksmith. Even Longinus can gain a Sub-Species Balance Breaker like Cao Cao's True Longinus' Polar Night Longinus Chakra Valdine or Sairaorg's Regulus Nemea's Regulus Rey Leather Rex.

Issei has been told by Azazel that he should develop a Sub-Species for Boosted Gear. This suggests that Sub-Species can be made both intentionally and unintentionally.

State Change Sacred Gears
State Change Sacred Gears are a type of Sacred Gears that changes the state of a user or another person/object. It can vary from doubling one's own power to healing wounds.


 * Known Sacred Gears of this type are:
 * Twice Critical
 * Twilight Healing

Creation Sacred Gears
Creation Sacred Gears are a type of Sacred Gear that allows the user to create matter/objects out of nothing.


 * Known Sacred Gears of this type are:
 * Sword Birth
 * Blade Blacksmith

Defensive/Counter-Based Sacred Gears
Defensive/Counter-Based Sacred Gears are a type of Sacred Gear that focuses mainly on defense and countering the attacks of the opponent.


 * Known Sacred Gears of this type are:
 * Mirror Alice
 * Night Reflection

Attribute/Elemental Sacred Gears
Attribute/Elemental Sacred Gears are a type of Sacred Gear that incorporates different attributes in its ability.


 * Known Sacred Gears of this type are:
 * Flame Shake
 * Sterling Blue
 * Sterling Green
 * Variant Detonation
 * Freezing Archaeopteryx

Time/Space-Based Sacred Gears
Time/Space-Based Sacred Gears are Sacred Gears that have the ability to manipulate time and/or space.


 * Known Sacred Gears of this type are:
 * Forbidden Balor View
 * Gravity Jail

Barrier/Sealing Sacred Gears
Barrier/Sealing Sacred Gears are Sacred Gears that have the ability to create barriers or seal an opponent or ability.


 * Known Sacred Gears of this type are:
 * Trick Vanish

Vritra's Sacred Gears
Vritra's Sacred Gears are the Sacred Gears that have a part of the soul of the Dragon King, Vritra sealed inside of them.

Chaos Break and Chaos Drive
A special doping for Sacred Gear made from the blood of the original Satans, created by the Hero Faction with the help of the Old Satan Faction. The doping, called Chaos Break, allows the Sacred Gear to undergo Chaos Drive, in which the Sacred Gear (and Holy/Demon Swords) fuses with the user while transforming the user into a monstrous form. The names are taken from the Balance Breaker and Juggernaut Drive. In Volume 12, it is stated that after the first use, each subsequent Chaos Break will reduce the user's lifespan. The injection is capable of giving the user a massive power-up at the cost of their bodies deteriorating to the point that even Phoenix Tears won't be able to heal them.

Trivia

 * Juggernaut Drive was originally stated to be a special ability which was exclusive for Sacred Gears with powerful creatures inside. Though in Volume 11, it was changed to a special ability exclusive for Sacred Gears with Dragons residing in them (Boosted Gear and Divine Dividing). For other Sacred Gears with other creatures residing in them, a new name, called Breakdown the Beast, was given.
 * In Volume 4, Azazel claims that the Sacred Gear system is incomplete due to the unforeseen deaths of both God and the original Four Great Satans which left "bugs" such as the Balance Breaker and Longinus behind.