Naruto Cursed Seals
Hyuga Branch Family Seal
This seal is given to all branch house members in the Hyuga clan by the main house. Its main purpose is to seal their Byakugan ability should they die, preventing an enemy from learning its secrets. Its secondary purpose is to control the branch house, since it can be activated at will by a main house member with a hand seal that only they know about. The seal is placed on the wearer's forehead at an early age, and is only removed upon their death. It works by destroying the wearer's brain cells.
In the original manga and Viz's volume distribution of the manga, the seal is shown as a manji, also known as a sauwastika or a sun wheel. In the anime and Viz's monthly distribution of the manga, it was changed to a simple saltire for fears of negative reactions, as the opposite-facing swastika was adopted as the symbol of the Nazi party.
Orochimaru's Cursed Seals
Orochimaru commonly uses cursed seals on his most powerful followers. To apply a cursed seal, Orochimaru needs to actually bite his intended target. Because he has sharp fangs and an extendable neck, this is a relatively simple task. The seal then appears somewhere on the user's body, and they subsequently lose consciousness. Sometime later, should they survive, they will awaken with the first level of the seal active and more than likely somewhat enraged. The seals work by forcibly drawing chakra from the user's body, giving the user a chakra capacity beyond what they would normally be capable of when active, as well as increased physical performance as a result of the increased chakra capacity.
The seals have two different levels, which can be determined by their appearance on the user. When inactive, the seal will simply be a black tattoo somewhere on the user's body. Orochimaru has a wide array of cursed seals, so the appearance of the seal will usually vary from user to user. Each seal always has three identical marks arranged in a circular pattern. When first activated, the marks on the seal glow and replicate, spreading over the user's body. This is known as the first level of the seal. The degree to which this occurs is dependent on the user, and the degree to which it spreads is proportionate to the overall effect it has. The second and final level of the seal causes the black marks to completely envelop the user. This is followed by an unnatural alteration of the user's body, with the only common features being yellow eyes with a black sclera (Sasuke's Sharingan is an exception). When in this level, the seal eats away at the user's personality, driving them to madness if used too long. It also takes quite a toll on their body, since they are being mutated by the seal.
Because the seals forcibly draw chakra from the user, they will often kill the user when first applied. Orochimaru has averaged a ten-percent success rate when applying these seals. Additionally, even if the user survives, their body will not be able to easily control the power the seals give them. To compensate for this, Orochimaru developed the Seishingan drug. The drug forces the user's body to become accustomed to the unnatural increase in power, but also kills the one who takes it. The Four Black Fog Formation Seal technique is used to keep the drug from killing the user by placing them in a temporary death state. Though Sound Four were the ones to perform the technique, it stands to reason that they weren't the ones that created it.
Orochimaru developed the cursed seals through experimentation on a prisoner named Jugo, whose body naturally produces an enzyme that triggers a state similar to the cursed seal. The difference between Orochimaru's seals and the unrefined enzyme are the effect they have: while the cursed seal is controllable, the unrefined enzyme produces uncontrollable rage in those exposed to it, including Jugo himself, and the effects cannot be controlled.
Cursed Seal of Heaven
Name: Ten no Juin, literally "Cursed Seal of Heaven"
Wearers: Sasuke Uchiha, Anko Mitarashi
This seal consists of three tomoe, like the Sharingan. It is the counterpart to the Cursed Seal of Earth, and the two seals are the strongest of all the cursed seals that Orochimaru uses. The seal spreads over the user's body like flame when activated.
Anko received her cursed seal while she was a student of Orochimaru. She, along with nine others, were the first people to receive a cursed seal. She was the only one to survive the application, hence the one in ten chance established by Orochimaru, but lacked the necessary will to use it. As such, her seal receded and Orochimaru wiped her memory. Orochimaru was able to reactivate it when they fought in the Forest of Death. It is possible that Orochimaru intended to use her as his next host, but was disappointed when he learned she lacked the malice to use the seal. Since Anko never uses her seal, her mutated form is never seen.
Sasuke also survived the application of the cursed seal. Orochimaru gives it to him against his will during the second stage of the Chunin exam. Orochimaru gave it to him as a test of the Uchiha clan's abilities, as well as a way to prepare Sasuke for becoming his next host. After Sasuke won his battle during the preliminary matches of the Chunin exam, Kakashi Hatake used the Evil Sealing Method, the effectiveness of which is dependent on the user's will to restrict the cursed seal. Regardless, Sasuke came to rely on the Heaven seal's power, thus weakening Kakashi's seal. Sasuke unlocked the Heaven seal's full power with the help of the Sound Four. When the second level of the seal is active, Sasuke's skin turns dark-gray and his hair grows much longer without losing its style. Additionally, he grows hand-shaped wings from his back and a dark, star-shaped mark appears on the bridge of his nose.
Cursed Seal of Earth
Name: Chi no Juin, literally "Cursed Seal of Earth"
Wearers: Kimimaro Kaguya
The counterpart of the Cursed Seal of Heaven, this seal was given to Kimimaro by Orochimaru in the hope that he might one day become his next host. Unfortunately for the both of them, Kimimaro contracted a fatal disease. The seal consists of three slightly curved lines, which spread in a square pattern. When the second level of the seal is active, Kimimaro takes on a dinosaur-like appearance, complete with a tail. Several large bones also protrude from his skin, and his skin becomes dark brownish-maroon.
Sound Four's Cursed Seals
Each member of the Sound Four uses a cursed seal. Their seals, however, are not as powerful as the Heaven and Earth seals, although they have similar end results.
Jiroubou's Cursed Seal
Jiroubou probably received the curse seal when Orochimaru was scouting for an army. The curse seal spread in a triangle style. His strength increases.
Jirobo's cursed seal consists of three triangles. When the second level of his seal is active, his skin turns red and his hair grows longer. He also grows warts on his forehead and shoulders. His level 2 curse seal grant him 10 times the normal strength.
Kidoumaru's Cursed Seal
Kidourmaru probably received the curse seal when Orochimaru was scouting for an army. The curse seal spread in a vine style. He is able to control and manipulate spiders and spider webs.
His level 2 curse seal turn him into a werewolf like. His skin turns red and has a fluffy hair and contain a third eye on his forehead. His body is protected and surround by spider web. His able to make bow and arrows with his mouth and shoot them. Kidomaru's cursed seal consists of three spirals. When the second level of his seal is active, a third eye opens on his forehead and his hair grows longer. He also grows horns on his forehead and his elbows.
Sakon and Ukon's Cursed Seal
Sakon probably received the curse seal when Orochimaru was scouting for an army. Sakon has a twin brother name Ukon that lives inside him. He's able to enter a person's body and destroy the person's cell from the inside. Ukon surface when Sakon summons him or on his own will. The seal spreads like a bold line.
Sakon and Ukon both have the same type of cursed seal, which consists of three irregularly-shaped dots. When the second level of their seals are active, they resemble ogres with red skin, a single horn (on opposite sides for each brother), and can grow armor from their bodies. They can also extend their fusing abilities to someone other than each other.
Tayuya's Cursed Seal
Tayuya probably received the curse seal when Orochimaru was scouting for an army. The seal spreads in a zigzag line
Tayuya's cursed seal consists of three hooks, similar to a triskelion. When the second level of her seal is active, her hair grows longer, she grows five oddly-placed horns, and her skin turns dark brown. The horns grow when she exerts herself.
Mizuki's Cursed Seal
Mizuki was shown to have received a mark similar to a cursed seal in the anime. This was not a cursed seal, however, but actually a blueprint to one of Orochimaru's forbidden experiments. Like Orochimaru's regular cursed seals, it glows red when activated, but the only accompanying change is the appearance of instructions on the tattoo. The experiment used a device to mix various animal-based chemicals into a digestible red liquid, which in turn gave the drinker animal-like abilities. Mizuki's tattoo, shaped like the device, identified the order in which to mix the chemicals.
After stealing the necessary ingredients from the Nara clan's medical laboratory, Mizuki created the potion and drank it. This increased his musculature, caused three tiger-like stripes to appear on his arms, and increased his physical attributes in much the same manner as a cursed seal. Additionally, he was able to channel all of his chakra into strength and the energy changed his appearance to resemble a tiger's. As a side effect of focusing all his chakra on strength, his speed decreased dramatically.
Though quite effective, Orochimaru neglected to tell Mizuki that the potion was so far incomplete, drinking it burned up all the energy in Mizuki's cells, leaving him a withered husk of a person. This would have killed him in normal circumstances, but Tsunade's medical expertise saved him from what would otherwise have meant his death. Unfortunately for Mizuki, the damage caused left him unable to ever continue his life as a ninja.