Like all spiritually aware Humans, Fullbringers can sense the Reiryoku of other spiritual beings, such as Hollows, Shinigami, and other Fullbringers. However, they differ in that they each have a parent who survived a Hollow attack before they were born. As a result, traces of the Hollows’ power remained in their mothers’ bodies, which were then passed onto them at the moment of their birth. Consequentially, their powers more closely resemble a Hollow’s than those of a Shinigami.
Their ability, called (完現術 (フルブリング), Furuburingu; lit. "Full Manifestation Art"), enables them to manipulate the souls contained within matter. Everything, even rudimentary objects such as lampposts and chairs possess a soul, however small. By using their power to “pull” on this soul, Fullbringers can manipulate the object's movement or even alter its physical characteristics. For example, Fullbringers could have a beverage assist them in drinking it by pulling on its soul, drawing it into their mouth. Likewise, by pulling on the soul of water, Fullbringers can walk across its surface without falling through. Many more feats are possible, making the technique highly versatile. Unlike other spiritual beings, Fullbringers use their power with their physical bodies. Because of this, they must train extensively to build up their stamina so they can use it properly.
While all Fullbringers are born with this power, the age at which they come to realize it varies. When Fullbringers die, all traces of their abilities disappear from the world. However, they do carry their abilities into the afterlife.
High-Speed Movement: Fullbringers can induce states of high-speed movement through Fullbring. Such movements are accompanied by the flickering of a green luminescence called (完現光 (ブリンガーライト), Buringā Raito; lit. "Full Manifestation Light"), which is the preliminary for each high-speed movement. This speed is achieved through a variety of different uses of Fullbring. By pulling on the soul of the ground beneath their feet, Fullbringers can increase its elasticity, greatly enhancing their jumping ability as a result. In addition, by Fullbringing the air around them, they can accelerate their movements. Doing so can consequentially strengthen the force of their blows. The ability to use this technique signifies that one is beginning to master Fullbring.
Object Affinity: By developing an affinity for a particular object, a Fullbringer can alter its form, granting powers that vary greatly among individuals. This affinity can be defined by one’s love for the object in question, or simply by an overall fondness for it. As such, this power is usually awakened through a strong emotion associated with the object, such as pride. Using this affinity, Fullbringers pull out the object’s soul and boost it with their own, transforming it in the process. For example, Kūgo Ginjō can change the saltire pendant on his necklace into a large claymore. While Fullbringers typically have an affinity with one such object, it is possible to have many. While all Fullbrings are unique, they can be defined by different types. For example, Fullbrings that shroud their users with their power are called (装衣型 (クラッドタイプ), Kuraddotaipu; lit. "Raiment-Type") Fullbrings.
Once a Fullbringer has fully realized this power, its abilities cannot and do not change through growth. However, Fullbringers must progress to a certain level before they can use their unique abilities to their fullest. As such, a Fullbring's various developmental stages can look radically different from its final form, and can thus be considered “incomplete.” When the Fullbring's potential is fully realized and it progresses to its final form, it releases a violent burst of energy that can potentially damage its user’s body. Because of this, another Fullbringer is typically required to oversee the process, and to prevent the recently completed Fullbring from injuring its user by suppressing the explosion. In addition, a Fullbring's growth can be promoted by exposure to the atmosphere of Hueco Mundo, as a result of its Hollow nature.
A Fullbring's unique power largely depends on the object that is used as a focus. In addition to souls, material objects also possess memories. As its holder experiences various events, the object experiences them as well; the memories are engraved onto its soul each time it is touched. Because of this, Fullbringers who had a considerable amount of battle experience prior to awakening their power have stronger Fullbrings.
Power Transference: Fullbring is a product of Hollow power, meaning that it is essentially the opposite of its Human wielders. Because of this, it is possible for Fullbringers to transfer their abilities to individuals whom possess the powers of both Shinigami and Humans – namely Substitute Shinigami. By doing so, Fullbringers can rid themselves of their power, effectively becoming ordinary Humans. In addition to Substitute Shinigami, Fullbringers can trade and share their abilities among themselves. When doing so, they can establish certain boundaries as to how their powers can affect one another, posing voluntary limitations. Finally, it is also possible for a Fullbringer to steal the Fullbring of another individual, allowing it to be used to one’s own benefit.