The Quincy are a line of spiritually aware human warriors. Originally a mixture of survivors of Hollow attacks and those who had lost loved ones to Hollows, the Quincy developed a variety of supernatural powers to hunt and kill Hollows before they attacked humans (and to destroy those who already had), including the ability to control Spiritual Energy. The Quincy are unique as far as races go in Bleach, because unlike the Hollow or Shinigami, Quincy are still technically human and reside in the world of the living.
Unlike the Shinigami, who use a sword as their primary weapon, the Quincy's weapon of choice is a bow. It is constructed from spiritual particles drawn from their surroundings, also unlike the Shinigami, who rely on their own innate spiritual energy (as a reflection of this, Quincies have white spirit threads like normal humans, while Shinigami have red spirit threads.) Quincy bows are summoned using an artifact called a Quincy Cross. The only limit to a Quincy's ability to create and fire arrows is their own stamina and ability to absorb ambient spirit particles. Quincies also have various tools and battle aides that can increase their power or serve as secondary weapons.
Another contrast between the Shinigami and the Quincy are their methods. While Shinigami purify Hollows, thus preserving the balance of souls between the two worlds, the Quincy destroy hollows, former soul and all. In doing so, the balance between the worlds is slowly tipped towards one side, endangering both worlds. This danger led to a Quincy-Shinigami war, which ended in victory for the Shinigami and the deaths of many Quincy. The Quincy line was closely monitored over the decades, as their numbers continued to dwindle. Later Quincy advanced the idea that since they were already among the living and still more numerous at the time, they could act as "first responders" to Hollow attacks, protecting humans until the less-numerous Shinigami could send a representative to finish the Hollow off. Embittered by the recent war, the Shinigami refused to participate, opting instead to allocate their limited resources to reacting to the most dangerous hollows and current Hollow attacks.
The final point of contrast between Quincy and Shinigami is their respective choice of uniform. While the Shinigami wear traditional, black, flowing hakama, the Quincy wear white, form-fitting, high-collared tunics. These bear some resemblance both to Mandarin Chinese dress and to the cassocks of Catholic priests. This gives the Quincy a distinctly "foreign" or "Western" style compared with the Shinigami. One peculiar recurring motif of Quincy is that of a cross, which appears frequently on their uniforms and artifacts. The cross is not the same shape among all Quincy.
Powers, Abilities and Combat
Quincy Bows & Arrows
All Quincies have the ability to create a unique spirit bow, and subsequently generate spirit arrows for the bow, using a Quincy cross or pentacle. The bow and arrows are both made up completely of reiryoku from the users surroundings, and last as long as the wielder's stamina and reiryoku reserves allow.
Reiryoku Absorption: Unlike Shinigami, who use their inner Reiryoku to fight, the Quincy fuel their abilities by absorbing the Reiryoku of their surroundings in the form of spirit particles. They primarily absorb them from the atmosphere, and have an easier time collecting this energy in environments with higher concentrations of spiritual particles, such as Soul Society or Hueco Mundo. To a sufficiently powerful Quincy, there is no difference between spiritual particles and spiritual energy as a source of power.
Reiryoku Manipulation: one can manipulate spiritual energy for offensive purposes. They most commonly reshapes spiritual particles into various types of bow and arrows, but can also concentrate spiritual energy into the form of swords or explosives.
Quincy Combat
The Quincy can also use the energy they gather, or use silver tubes filled with spiritual energy (see below), to perform various offensive, supportive, and defensive techniques similar to the Shinigami Kidō.
A Quincy's power can be significantly enhanced using the Sanrei (散霊) glove. A Quincy needs to complete a week of intense training in order to be able to use the glove. The glove operates by repelling spirit particles, making it far more difficult for the Quincy to summon their bow. Any Quincy who is able to successfully utilize their powers while wearing the glove can thus reach much higher levels of power. This training is also the basis for the Quincy final form
A Quincy who wears the Sanrei glove may remove it in desperate cases, entering a state known as the:
Quincy Final Form: The Quincy Final Form gives the user a tremendous amount of power, but at the price of their powers upon it's completion.
The only way for a Quincy to regain their powers after using the final form is to first exhaust themselves both mentally and physically, then be hit exactly 19 mm to the right of their heart with a spirit arrow. After this, a pentacle-shaped scar will form on the point of impact, and their powers will be restored.
Quincy Items
The Quincy possess numerous artifacts and equipment which help them in different ways. Below are the ones that have been shown:
Hollow bait — This item is a small, coin-shaped disk that attracts hollows when crushed.
Quincy bangle (装身具, sōshingu): The Quincy Bangle is an artifact designed to mimic a Quincy's natural powers. It works by drawing in spirit particles from the environment, much like a Quincy does regularly. It can only be used properly by those who are already adept at forming and directing spirit particles.
Quincy cross (滅却十字, mekkyaku jūji) — Standard equipment for any Quincy, the Quincy Cross acts as the focus for a Quincy bow. The cross need not necessarily be in a cross shape.
Sanrei Glove (散霊手套, sanrei shutō): The sanrei glove is a powerful Quincy artifact that can increase a Quincy's power exponentially, but requires a dangerous and exhausting type of resistance training (wearing it for a week while constantly firing spiritual arrows) to master. The glove works by scattering the spirit particles in the surrounding area, making it much harder to form a working bow. If a Quincy can summon a bow and use it for the required amount of time, they will have undergone a massive increase in power. When removed, however, the glove will release the user's energy all at once - first transforming them into a being of tremendous strength, the Quincy Final Form, and then forcing their Quincy powers to gutter out completely.
Seele Schneider (魂を切り裂くもの(ゼーレシュナイダー), kon wo kirisaku mono; lit. that which slits the soul; German for "soul cutter"): The Seele Schneider is a thin sword that can be fired similarly to an arrow. It's much longer than a standard arrow and functions something like a chainsaw: the spirit particles of its blade vibrate at ultra-high frequencies, loosening the molecular bonds between any spirit matter it cuts so that the Quincy user may easily absorb the freed spirit particles.
Silver tubes (銀筒, gintō): Silver tubes are small liquid-filled capsules that store spiritual energy, and are used by Quincy for spellcasting in the same way that Shinigami use kidō. Like kidō, they are activated by calling out various commands.
Quincy Techniques
Hirenkyaku (飛廉脚; lit. "flying screen step/god step"): Analogous to the Shinigami Flash Steps or the Arrancar Sonído, the Quincy Hirenkyaku allows the user to move quickly over short distances. To perform the technique, the user gathers spiritual particles under their feet and rides them to the desired location. Like the air-walking skill displayed by most Arrancar and Shinigami(Sonido and Shunpo), it can also be used to hover or fly for long distances.
Ransōtengai (乱装天傀; lit. "heavenly wild puppet suit", "disheveled paradise puppet" in the Viz translation) — this is a high level technique that allows the user to control their body parts using strings of spirit energy controlled by their brain, forming lines or strings out of countless spiritrons. By using this technique, the user can control their body as one would a puppet, allowing them to move freely despite paralysis, broken limbs, or any other force that would impede normal movement. Dislocated joints and broken bones are meaningless against this technique.