Innocence

Innocence is the power source that drives the Black Order. Innocence is also the weapon that Exorcists use to defeat and purify Akuma.

Innocence is used by exorcists chosen by the innocence to wield them. Each piece of innocence is different and is specifically created for their use. Innocence is somewhat sentient and can make up it's own mind who it will use as a host or something else.

The Innocence was originally a golden cube, inscribed with what is described by Hevlaska as an ancient prophecy: ''Our descendants, We have battled the darkness, and they are a dying breed. There will be calamity in the future, so we leave behind this message here in order to help you.'' It is revealed that the cube was made by people who had fought the Millennium Earl, and in the process the world was destroyed by a great flood, where only Noah and his family survived. The cube was eventually scattered into 109 pieces around the world.

One part of the Black Order's agenda is to find all the Innocence shards as well as their compatible users to defeat the Earl and his followers. The Innocence is the only thing that can destroy Akuma without destroying its soul, and hurt the Earl and members of The Noah Family, but only the last two have the ability to destroy shards of Innocence by crushing them in their hands. At least 12 pieces of Innocence have been destroyed by them so far.

If a piece of innocence has decided that the one using it has sinned or will not recognize the current user anymore as it's master, the exorcist will become a fallen one. This is where the innocence completely takes over an exorcist's body and turns it into a monster of innocence destroying everything surrounding it. There is no current cure for this and eventually the one afflicted will burn out and die. Allen managed to stop a fallen one by removing the innocence itself from the exorcist, but by then the fallen one had lost it's mind and become a comatose, non-responsive person.

Innocence types
There are three types of innocence forms:

Equipment
The most common of the innocence forms. This is where the innocence is forged into a weapon and is used by the chosen exorcist. Each equipment innocence is forged differently to accommodate each exorcist's unique innocence abilities, such as Kanda's sword or Lenalee's boots. Because the Innocence is not physically in contact with its Equipment-type Accomodator, the Exorcist cannot control the weapon as well as a Parasitic-type can. However, it is revealed in the anime that members of the Noah family can extract the Innocence from equipment-type weapons easily if given the chance.

Parasitic
A rare type of innocence where the innocence is born with the person and serves as a weapon. Though the cells that make up this type of innocence are not part of the person, the body still recognizes it as it's own. Because the Innocence is a part of the Exorcist's body, it can heal the Exorcist if he or she is hit by the Akuma's Blood Bullet, destroying the virus before it can spread. The side effect of this innocence is that the user's appetite increases due to the innocence feeding off the person, so in reality the person using the innocence is literally eating for two people. Also, the Innocence eventually weakens the user as it draws its energy from the host's body, which reduces the user's lifespan.

Crystal
A new type of innocence where blood is the innocence's medium. The power of this type is incredible as Lenalee used this type to help defeat a level four akuma. The full power of this type has yet to be seen. There is no telling what this type will do to the person in life. Currently the order is recording all uses of this type and finding out what it can do as well as find out what would happen to the person using it. The Innocence takes a metallic form created from the Exorcist's blood. Although the Innocence can be controlled through emotions like a parasite-type, no part of the user's body is altered. Instead the Innocence resides in the crystals made from the Exorcists blood forming an object such as a ring, or in Lenalee's case, a pair of bangles around her anckles. When the user activates the innocence, the item transforms into a weapon of sorts, similar to equipment type, but not actually part of the body like the parasectic type.

The power of innocence is determined on how much an exorcist is in synch with his weapon. The higher the synch rate the better the weapon is. Also, Exorcists who have achieved certain synch rate with their Innocence can advance it to Level Two if neccessary. This can allow them to access more powerful skills that cannot be used at basic invocation. Most exorcists have a synchro rate of about eighty or more but generals are the only ones that can bring their rates up to one hundred percent and beyond that.

If a synch rate falls below ten percent it is too dangerous to use the weapon, as the exorcist could become a fallen one.

Heart of Innocence
The Heart of Innocence is a shard of Innocence that contains the source of power of all Innocence shards. It is unknown what it exactly looks like but it has been speculated that the Heart holds much more power than an ordinary Innocence shard and reacts in even stranger ways than usual. However, should the Heart be destroyed, every other piece of remaining Innocence would shatter along with it. Currently, both the Earl and the Order are trying to find the person who has it and or where it is. The side that finds it first would hold a large advantage over the other, and finding it is one of the key agendas of both sides.

Lenalee Lee or Allen Walker are theorized to be the wielder of the Heart, due to their powers and the unusual behaviors they have.