Guardian ADA

ADA (エイダ, An acronym for 'Artificial Digital Apparition') as well as a shortened version of Adelaide meaning "Noble" in German, is the entity created by Ishida Ryuichi in his attempt to create a Zanpakutou. As implied by her name, she is an artifical spiritual entity originating from a digital device. After his many encounters and increasingly powerful foes, Ryuichi dedicated most of his time to finding a means of acquiring even more power, specifically those of that of a Shinigami. In their initial meeting however, ADA went berserk nearly killing him. Only after he had subjugated her, was he able to restore her sanity, and bestowed her name. This is unlike other Zanpakutou who must strive to get their Shinigami to hear their name, as opposed to it being given by the wielder.

Appearance
ADA in her humanoid form, takes the appearance of a woman of average height, with waist-length long raven colored hair and eyes. She wears a dark-green almost grey colored bow in her hair, and wears what appears to be a modified white and black sailor uniform. She wears some sort of armor, as she sports black shoulder pauldrons, and gauntlets. On her chest is a crimson orb resembling an eye. Black lining runs down the front of dress which hugs her body, with a small opening exposing her stomach. Below it opens up into a black skirt, and thigh-length black boots, which on her right are black grieves. Her most unique features are the two raven like wings protuding from just above her waist, and the monstrously sized ornate arm-cannon affixed to her right arm. ADA has a rather unique composition, being made up of both spiritrons, and a loose network of spiritual nodes. Her form is held together in the physical sense however as she is visible by normal humans, and interacts with the environment as any human would and not a spiritual creature. But like a Zanpakutou she also resides within Ryuichi, in fact existing in both his Inner World and in the physical simultaneously. So even if her physical form is destroyed, so as long as Ryuichi has more spiritual nodes available, she would be able to reconstruct her form again.

Powers & Abilities
Intelligent Device (インテリジェントデバイス, "Interijiento Debaisu"), as the name implies, ADA is a device that incorporates sophisticated artificial intelligence in her programming, combined with an artificial soul, enabling her to have autonomy. However she recognizes Ryuichi as her "master" and obeys his commands explicity.

Spiritual Cross Link (霊力クロスリンク, Reiryoku Kurosu Rinku): ADA is a unique entity, serving as a cross between a Zanpakutou and a Quincy Pentacle. Thus she is acts as a focus for his spiritual power, channeling and stablizing his spiritual energy input and output. Furthermore, ADA provides what she refers to as a Boost Drive (ブーストドゥラブ, Būsuto Durabu), an ability wherein Ryuichi's spiritual energy output is directly strengthened and accelerated, greatly empowering his abilities. ADA interfaces with Ryuichi through resonating at his spiritual frequency. This provides a number of functions, most notably it allows ADA and Ryuichi near telepathic communication, and faciliates the use of her "Boost Drive".

Technological Assimiliation System (テクノロジーアシミレイションシステム, Tekunorojii Ashimireishon Shisutemu): ADA is capable of assimiliating new technologies into her form and incorporating them into her system. She does so by breaking down the device apart to its most basic components, then reassembling it as it is literally absorbed into her being. Once a piece of technology has been adapted ADA can then use it thereafter however she see's fit, although it is generally at the discretion of Ryuichi.
 * Technokinesis: ADA demonstrates the unique ability to communicate and manipulate any machine or device within range of her spiritual pressure. It is this ability which allows her to hack into virtually any computer system or other device.

Behind the Scenes

 * ADA's name is inspired by an AI of the same name of Jehuty in Hideo Kojima's Zone of the Enders.
 * ADA is the third character to have an appearance based off of a Touhou character - Reiuji Utsuho.