Identity Thief

Identity Thief(アイデンティティの盗人; Aidentity no Nusubito ), also known as the The Body of the Bandit is a longinus-tier Sacred Gear featured in a upcoming fanfiction.

Summary
A relatively unheard of Sacred Gear, Identity Thief is a common Sacred Gear that fulfills a more "infiltration" role. Due to the most powerful beings in the world not really requiring stealth to fulfill their objectives, the Sacred Gear is usually shot down as a lower tier. However, Identity Thief has numerous abilities depending on what the user's species is.

Abilities
The most common usage of this Sacred Gear is obviously assuming another person's appearance, voice, and habits. The most well known application of this ability is when a former human accidentally assumed the identity of Sirzechs Lucifer, causing a great panic in the underworld as the user does not obtain the memories of the identity they stole. However, a user cannot assume an identity for longer than five minutes.

When used by a human, the Identity Thief allows the user to use Demonic or Angelic powers and obtain the body of a Devil/Angel temporarily. However, even though the amount of power they obtain is negligible, if they were scanned by a Magic detector or something of the sort, they would have the amount of magic the identity would have. For example, if a user stole http://highschooldxd.wikia.com/wiki/Rias Gremory Rias Gremory's] identity, they would have the artificial power of a High-Class Devil.

If a reincarnated Devil possesses the Identity Thief, they are allowed to obtain Clan Traits from a Devil's identity they assume. However, as the user is initially a Devil, they can no longer assume an Angel's identity, but they retain the ability to assume a human one. An example of it's application is temporarily taking the form of Bedeze Abaddon to gain the ability of the House of Abaddon's Power of Hole.

Finally, an Angel possessing the Sacred Gear would be able to fake the "holy" element of a identity. Just like the case of a Devil, the user cannot use the form of any Devils as they are opposing beings. In a case of a Angel possessing Excalibur, while they would not be able to wield it due to the sword rejection them, they can assume the identity of King Arthur and temporarily become it's true wielder with the sword accepting them. Just like the Devil variant, they can still assume a identity of a human.

Forms
The Identity Thief is a Sacred Gear without a form, much like Forbidden Balor View. Instead of being located in the user's eyes however, it is placed as the user's body. When using the ability, the user will temporarily lose their form and become a pure white being with black spots all over them before settling into their new form.

Existence Swindler
The Balance Breaker form of Identity Thief. While using the Balance Breaker, the user ignore's limitation of being locked to five minutes. In this mode, the wielder does not need to follow the conventional "rules" per say, a Angel can have the Bael's Power of Destruction and a Devil can wield the power of Durandal. A human will be able to fully gain the power of the identity assumed, but they will not be able to wield the abilities of the person to a strong level due to lack of practice. Even if the user practices the Water magic of Sona Stiri's clan, they will be locked at half the strength of the user because their original human mind cannot handle the strain. When the Balance Breaker is active, the user's transformation color scheme will be reversed.

Trivia

 * The image for this particular Sacred Gear is taken from a chapter of Reincarnation no Kaben
 * It is unknown what abilities another species could attain from this Sacred Gear as they do not have a reincarnation system.