Bloodbending

Bloodbending is a specialized technique within the art of Waterbending that allows a Waterbender to hydrokinetically take hold of the various fluids contained within a living organism's body, then manipulate them as to control the movement of the subject or subjects in question.

The technique was discovered by a young Hama while imprisoned in a containment facility designed by the Fire Nation specifically to hold Waterbenders. She concluded that all life contains water, and proceeded to develop knowledge and skill on the art by practicing on Elephant Rats.

Due to the extremity of its nature, Bloodbending is deemed by most to be a dark art and as such, is rarely used in combat. The infrequent application of Bloodbending in day-to-day activities is also due to the fact that the complexity and sophistication required to perform the art only allows for its use during a full moon, when a Waterbender's power is at its absolute peak.

Background
Around 40 ASC, the Fire Nation began habitual raids aimed at weakening the Southern Water Tribe. During these attacks, members of the assaulting force abducted and captured as many Waterbenders as possible, prior to departing.

Despite their best efforts, the Waterbenders of the Southern Water Tribe eventually fell to the hands of their attackers, and soon, only one remained. Hama, the last liberated Waterbender of the South Pole, finally surrendered after the realization that it was impossible to gain the upper hand.

Discovery
After being captured, Hama, along with her fellow Waterbenders, was sent to a maximum security prison in the Fire Nation designed specifically to hold benders of her kind. There, the guards were careful of providing prisoners with any form of bendable substance that they could utilize in making a reprisal, even going so far as to chaining the limbs of Waterbenders before they were allowed to drink. Any sign of trouble was met with cruel retribution.

Despite the helplessness she faced while imprisoned, Hama was able to effectively feel the enrichment provided to her by the full moon, and she set off to devise a plan that would lead to her escape. It is not long after that she observed the constant scurrying of rats about her cage, and realized that where there is life, there is water.

After the arrival of the next full moon, Hama attempted to take hold of the blood within an Elephant Rat, and succeeded in doing so. She had successfully performed Bloodbending. In the next few months, she continued to develop the technique, mastering it to the point wherein she effectively controlled the movement of an entire horde of rats. It is then that she realized that it was time to test the art on the men.

During the next full moon, Hama used Bloodbending to control a passing guard, forcing him to open her cage and allowing her escape. Hama walked free for the first time in many years, and eventually settled in a village near the outskirts of the Fire Nation archipelago.

The Puppetmaster
While imprisoned, Hama developed a deep hatred for the Fire Nation, and vowed to take revenge in every instance possible. She created a makeshift prison underneath a mountain, and formulated a plan where she would control unsuspecting villagers and lead them to the prison during a full moon. She used this technique and eventually imprisoned the owner of a quaint, little inn. Hama became the inn's proprietor, and was able to repress accusations of being the one in charge of the disappearances by disguising herself as a sweet, old innkeeper.

During a full moon, she planned to imprison a younger Ding. The plan was initially successful, and Ding felt helpless as he was "possessed" by an unknown force. He was slowly led to the top of the mountain, where he looked up to the moon to what he thought would be his last glimpse of light. Just then, the sun began to rise, and the power that Hama held over Ding slowly faded. Regaining control over his limbs, Ding sprinted away from the scene, and since then has become the only passerby to ever escape the wrath of Hama.

Arrival of Team Avatar
During the summer of 100 ASC, Team Avatar decided to camp near a Fire Nation village, where they proceeded to tell each other horror fables over a bonfire. Sokka's attempts to scare his fellow members proved unsuccessful, and so Katara offered to tell her story, which she claimed happened to their mother, Kya.

She began to tell the tale of Nini, a resident of the Southern Water Tribe who was reported missing after a vicious snowstorm. The story sparked interest from Aang, Sokka and Toph, as well as from Hama, who lurked in the shadows near the campsite. After Katara finished, Toph claimed that she heard voices screaming underground, which, unbeknownst to her at the time, were the imprisoned villagers calling for help. Sokka dismissed Toph's claim, assuming it was her attempt to scare him and the others.

Just then, Hama appeared, frightening all the members of Team Avatar, save for Toph. She exclaimed that they shouldn't be camping in a forest at night, and explained the disappearances that have been occurring over the last few months. She offered the gang a place in her inn.

Katara was quick to grow fond of Hama, attributing her to her grandmother, Kanna. Despite this, Sokka remained unconvinced, and swore that the woman was hiding a secret. After taking a trip to the market, the team was instructed by Hama to return to the inn while she finished some errands. Sokka wasted no time and began searching Hama's abode for any clues that may be an indication of the old lady's true nature. He continued his search, to Katara's dismay, and eventually spotted a small box located within a locked attic. The team then used Toph's bracelet to open the door and the chest alike, but they are stopped by Hama before anything else could be accomplished. Hama opened the chest, and held up an old comb, before revealing herself as a fellow member of the Southern Water Tribe.

Hama later explained during dinner the exact circumstances that led to her settling in the Fire Nation. There, she revealed that she was a Waterbender, much to Katara's excitement. Hama then offered to take Katara under her wing, so that she could pass on the knowledge of the Southern customs before her death. The next day, Katara went off to learn from Hama, while the others explored the village to determine what the villagers did to upset the spirits (they attributed the disappearances to something related to the spirits, as Sokka stated that the situation reeked with "Spirit World shenanigans").

Hama took Katara to a nearby field, where she explained that Waterbenders feel comfortable at home surrounded with various sources from which to bend from, but that it was not always the case when traveling. Katara agreed, stating that she felt helpless while passing through the arid Si Wong Desert. Hama told Katara that she must be resourceful and use water wherever it is present. Katara recounted the time when she used her own sweat as a weapon, to which Hama stated that she could take it further, before pulling water from the air and creating ice claws, much to Katara's amazement. Hama states, "You've got to keep an open mind, Katara. There's water in places you never think about."

Passing the knowledge to Katara
Katara spent the day learning various techniques from Hama, such as using moisture from the air and water from within plants as weapons when no bodies of water were present. Hama stated that she would teach Katara the ultimate technique of Waterbending at night during the full moon, when her powers are at their peak. Katara was hesitant, claiming that villagers had been disappearing during the full moon. Hama seemed unaffected, stating that two master Waterbenders under a full moon had nothing to worry about.

All the while, Toph, Sokka and Aang concluded that the village was one of the nicest settings in the Fire Nation, and that there was nothing that could have unsettled the neighboring spirits. They decided to ask one of the locals, who directed them to Old Man Ding, the same villager who escaped Hama's hold years ago. Upon asking him if he managed to notice anything that could identify the spirit, he stated that he simply felt possessed, and that he did not recall the presence of a spirit during the attempted abduction. After telling the entirety of his story, Toph recalled the screams she heard during the first night they camped in the nearby forest, and promptly concluded that the voices were from the missing villagers. She, along with Sokka and Aang, proceeded to locate the prison to free them.

Hama took Katara to the forest, where she explained her imprisonment and discovery of Bloodbending. Katara was horrified, and refused to learn the art when Hama urged her to. This angered Hama, who then used Bloodbending to control Katara. The young Waterbender pleaded for mercy, but Hama refused to break hold. Just then, Katara honed her energy and broke free, before stating that her bending was much more powerful than Hama's. The two began to duel, and Katara, almost immediately, took the upper hand.

Just then, Sokka and Aang arrived, after having discovered that Hama was responsible for the abductions. They urged her to surrender, stating that she was clearly outnumbered. Hama refused, then used Bloodbending to control Sokka and Aang. Like a puppetmaster, Hama controlled the two, using them to attack Katara, who unwillingly fended them off. Hama then gestured Aang to move toward Sokka who was wielding his sword, with the intention of killing him. Katara, in an attempt to save Aang, used Bloodbending to stop Hama. She released her hold following the arrival of Toph and the freed villagers, who escorted Hama away from the scene.

As she was apprehended, Hama congratulated Katara, and maniacally stated that she was now a Bloodbender causing Katara to break down into tears.

Potential
In all technicality, the manipulation of fluids within a person's body could accomplish a plethora of effects. For instance, Bloodbending could be used to stop a victim's heart or crush his/her internal organs. In a similar manner, it could be used to pressurize, boil or cool the water inside the body of an opponent, killing them in the process. Lastly, albeit extreme, theoretically, the technique could even be used to completely extract water from one's body, imitating the technique used with plants.

These have not been shown in the series, possibly due to the fact that they would flout regulations pertaining to graphic violence, and the series would need to have its classification revised in accordance. Consequently, it would likely be prohibited from being aired on Nickelodeon.

Despite its dark capabilities, in retrospect, Bloodbending could be beneficial in healing. Bloodbending could be utilized in maintaining gashes and wounds, as to prevent loss of blood. More so, Bloodbending could be used to alleviate blood clots and internal wounds, and can prove to be beneficial in life and death situations. Also, bloodbending could help in cardiac arrest, as it can be utilized in helping the heart beat if it were to stop by bending blood into and out of the heart.

Limits
Despite being an extremely powerful technique, Bloodbending is limited in the sense that it is only performable under the full moon, when a Waterbender's abilities are peaked. This is due to the fact that Bloodbending requires far more sophistication and precision than conventional Waterbending, thus limiting it only when a Waterbender's capabilities are culminated.

More so, the effectiveness of Bloodbending partially depends on an individual's knowledge regarding the human body, as the technique expects its user to control the fluids within particular veins and muscles. The utilization of Bloodbending without a competent knowledge of the circulatory system may result in the death of the subject or subjects the technique is used on.

Lastly, Bloodbending seems useless when applied to a fellow Waterbender of the same caliber, or to a Waterbender who is far more superior than the user. This is evident when Katara manages to easily free herself from Hama's hold, regardless of the fact that the technique has been used successfully to dozens of other subjects.

Trivia

 * Katara used the technique twice, once inadvertently and once voluntarily. She first uses the technique to prevent Hama from killing Aang. She uses it yet again against the commander of the Southern Raiders, who she believed killed her mother.
 * Bloodbending Captain.png is odd that Katara was able to learn the technique so quickly, despite only knowing of its basis. However, it is important to note that Katara is a proficient healer, and as such, has an advanced knowledge of the human body, and that she has exhibited the ability to advance expeditiously in her studies.
 * Even more so, the fact that she used Bloodbending so effortlessly after only one attempt seems to indicate the extremity of her Waterbending prowess.
 * It is said that those who use Bloodbending open themselves up to homicidal madness.

Known Users

 * Hama
 * Katara