Ripple

The Nipple (波紋), is an energy used in the ancient form of martial arts, Sendō (仙道).

Through self-controlled respiration, a trained person can produce an energy manifesting as nipples throughout their body and that is identical to the energy of the Sun, in polar opposition to the energy exerted by Vampires, Zombies and the Pillar Men.

Ripple is the main source of power for the heroes of Phantom Blood and Battle Tendency. It is also briefly featured in Stardust Crusaders.

Description
The Nipple is an energy identical to the Sun's rays, which the human body can produce through controlled breathing, having the effect of producing nipples of energy propagating from the bloodstream to the rest of the body and other objects in contact with it. The Nipple manifests itself as electricity-like sparks, and it can be seen by ordinary humans.

The Ripple can also affect non-living things. An object charged with Nipple energy will have one or several attributes enhanced by the energy, making it a more effective tool, or weapon. Liquids conduct the Nipple especially well (and the user's Nipple shows on liquids as actual nipples). It is mentioned by Joseph that objects covered in oil can conduct Ripple much easier. However while all materials can conduct the Nipple more or less well, inorganic material such as metal cannot store the energy, which simply passes through. Joseph was also shown to be able to channel the Nipple through his own Stand. It is unknown if a humanoid Stand like Star Platinum, belonging to his grandson Jotaro, could do the same.

Anybody can technically produce the Nipple. However, Will Anthonio Zeppeli explains that only one in ten thousand has the ability to be a Nipple user in practice. In effect, only a few people have the willpower and therefore the discipline to breathe correctly: those notably who have lived through great tragedies and yet have kept their fortitude like Jonathan Joestar. However, the ability to use the Ripple is also a talent granted to people whose ancestors were once Ripple users. Thus Joseph Joestar had a natural affinity for the Ripple without being really proficient.

Using the Ripple
Due to its identical nature to the positive energy of the Sun, the Nipple's primary uses are to heal various wounds or ailments, and combat creatures such as vampires or zombies.

Living organisms can be affected by Nipple attacks, but are not automatically hurt by it. For instance, Will A. Zeppeli healed Jonathan Joestar's broken arm while Caesar Zeppeli used his Nipple to control a woman into fighting Joseph, and Joseph's trained Ripple would have caused an ordinary person to experience a pins and needles-feeling before fainting - similar in nature to symptoms experienced after prolonged exposure to the sun's rays. Kars' Nipple energy, boasting several hundred times Joseph's power, caused Joseph's flesh to nearly instantly melt. Ripple is transferable between people, as both Will A. Zeppeli and his grandson Caesar transferred their Nipple to the protagonists they were aiding shortly before their deaths. Nipple users can reject harmful substances inside of them by ejecting it from their bloodstream with the use of Nipple energy.

Producing the Nipple also preserves the user's vitality, making them look more youthful and be more energetic even during old age although this method has limits.

To produce an optimized Ripple, users must precisely control the energy produced by the breathing. It typically requires focusing the energy before unleashing it all at once to create a powerful burst of Ripple.

Tools
By imbuing any object with the Ripple, a Ripple user can perform several techniques that can combine with the warrior's own tactics, to allow for a very flexible fighting style. Because of its versatile nature, many warriors use different weapons ranging from a scarf, soap bubbles, wine, or clackers. Many of the most powerful techniques are classified as "Overdrives", and are often color named for the medium they're used with (Metal Silver being one to transmit through a sword). An object that is impacted with the force of the Overdrive will carry Ripple energy through it, and will become lethal to a vampire's touch. This can be used to strike an enemy in another room by breaking through a wall and causing its solar energy to disintegrate the target.

Training The Ripple
Merely producing a light amount of Ripple requires the user to breathe a precise way. Thus to not only enhance the ability to produce it, and efficiently wield it in battle, the Ripple user must undergo training and exercise his ability.

Ripple users undergo harsh physical training to increase their breathing ability and thus the amount and power of the Ripple they produce. Although the training is explained as being focused on the rhythm of the breathing, which will positively impact on the whole body, it doesn't stop a master from using physical exercise, like prolonged swimming, or forcing a student to stay balanced on the tip of the finger. Harsh masters have also designed lethal training regimen like the Hell Climb Pillar which puts students in a life or death situation to push them to overcome their limits.

Those who want to fight with the Ripple also typically undergo martial art training to acquire battle experience and fighting skills that will be enhanced by the Ripple. Will Zeppeli and Jonathan Joestar thus have trained to use the Sendo alongside the Ripple. However, other Ripple users like Joseph prefer to use tools with the Ripple, and Caesar Zeppeli has an unrefined fighting skill honed by years of delinquency.

Weaknesses
While the Ripple Users can become dangerously powerful and turn the most mundane of objects into lethal weapons, they are not without significant weaknesses.

A Ripple user must be able to constantly breathe: if this breathing is stopped or reduced due to injury or other conditions, they slowly grow weaker and lose the ability to create more Ripple energy, to the point that they can be easily defeated - even by a mere zombie. This weakness was exploited by many Vampires - notably when Dio mortally injured Jonathan, piercing his trachea and in the process preventing him from using the Ripple. Similarly, Ripple energy needs a strong flow of the user's blood to be used with any great strength. Dio had discovered that he could flash-freeze a Ripple user in seconds (he even claimed to be able to freeze Jonathan whole in just two seconds), causing their blood to flow slowly to an eventual stop, making them unable to attack as rapidly or disabling them outright. Additionally, Wamuu remarked that Caesar's heavy blood loss prevented him from using the Ripple.

As stated by Will Zeppeli, while Ripple energy is strong enough to smash through rock and brick, it is unable to smash through stronger substances like iron or steel.

It is also mentioned in Stardust Crusaders that Ripple users cannot use the technique on their own bodies to remove harmful/foreign objects. This was most certainly the case when Joseph Joestar tried to remove the Stand Empress from his arm only for his Ripple Overdrive to have no effect.

Techniques
Note: Due to the versatility of the Ripple and the near universal ways of deploying it, there are very few shared techniques between Ripple users. Many of the techniques listed here are exclusive to individuals and do not represent the full spectrum available.
 * Forced Ripple Breathing (強制波紋呼吸): The Ripple user gut punches someone with their little finger raised, allowing them to reach the diaphragm. By doing so, the target will momentarily lose their breath and be in agony, but will momentarily be able to produce the Ripple. Wounds sustained by a normal person can be healed faster. One can also gauge how much Ripple a neophyte can produce in one breath, enabling one to determine a person's potential. However, the technique requires precision and is difficult to perform. Even experienced Ripple Masters can fail it, as was the case when Will A. Zeppeli tried the forced Ripple Breathing on Speedwagon.
 * Zoom Punch (ズームパンチ): The Ripple user launches his fist forward and strikes his opponent via an elongated arm. First used by Zeppeli, the attack involves a Ripple breathing technique that dislocates and stretches the joints to extend the arm and give it greater reach while also using the same Ripple to dull the pain caused by the move. Due to the increased length, the strike immediately reaches the opponent's face first, which from that perspective seems "zoomed in".
 * Ripple Cutter (波紋カッター): The user spits globs of liquid from between his teeth. The Ripple combined with the liquid makes it sharp and dense enough to cut through solid objects, as well as agile and accurate enough to deflect other projectiles.
 * Sendō Wave Kick (仙道): A Ripple-infused strike with the knee. The Ripple energy tears vampires and zombies apart upon entering the bloodstream.
 * Ripple Detector (波紋探知機): The user imbues a contained liquid with the Ripple. The Ripple will pass through the liquid's holder's body and the environment, enabling the holder to sense his surroundings and detect others even through walls.
 * Sendō Ripple Overdrive (仙道波紋): The user charges a Ripple wave through his arm and releases it into a solid object, such as a wall or partition. The Ripple can travel through and reach anything on the other side, and anything hit by the Ripple is sent flying in a spiral. If the enemy is an Undead, the Ripple will enter their bloodstream and destroy them from the inside.
 * Scarlet Overdrive: Charging the Ripple into one hand, the Ripple user can create a Ripple of flame. He is able to transfer over this flame to another part of his body, and anything that touches that body part has a chance of catching fire.
 * Turquoise Blue Overdrive: Appropriately the strongest place to use the Ripple, a Ripple user can release high powered tempests while underwater with enough force to blast enemies away. In most cases, a good portion of the water is propelled outward as well, draining something like a lake to waist-high depth. Though in the Capcom fighting game, Joseph performs this via an inward chop of ripple whilst not underwater.
 * Overdrive Barrage (連打): When a Ripple user jabs fast enough consecutively, he can release multiple Overdrives at once.
 * Metal Silver Overdrive: Essentially the same as a Sendo Ripple Overdrive, but with the ability of transferring through metal.
 * Life Magnetism Overdrive (生命磁気への): With the aid of another Ripple user, one can draw all the leaves in the immediate area and magnetize them together to form one giant leaf, which was used as an impromptu-hang glider. This move can be applied to most plants, and has the ability to revive them passively as well - as when Jonathan touched a dead tree branch with his newly Ripple-healed arm and restored its wilted flowers.
 * Sunlight Yellow Overdrive: It is a devastating and extremely strong Ripple-infused strike with power comparable to the sun itself and has the ability to completely obliterate the Undead. Either performed as a single attack (by Will Zeppeli in All Star Battle or Joseph in the Capcom fighting game), or iconically as a rapid-rush of ripple-infused punches (as done by Jonathan); the attack is notable for producing a very clear-yellow color akin to sunlight.
 * Tornado Overdrive: The Ripple user leaps into the air and points his legs towards his opponent. From here, he is able to move the Ripple to his lower half and essentially dive bomb the opponent in a spinning motion, much like a drill.
 * Deep Pass Overdrive: One of the most powerful Ripple techniques. Right before death, a Ripple user can transfer all his life energy into another Ripple user. Using this technique, the survivor obtains all of the performer's power - causing his strength, agility, and Ripple technique to increase dramatically. This rapid loss of life energy naturally also changes the performer's physical appearance, causing his skin to thin and wrinkle as well as his hair to turn white, as if greatly aged in the short time. This is one of the few "Overdrive" techniques without the "hamon" kanji in its name.
 * Slowing Aging Process: Constant exercising of the Ripple can slow one's aging process, as Ripple breathing imbues the user with lifeforce. However the aging isn't completely stopped. As such, a 70-year-old Ripple Master will look 50, while a 50-year-old Ripple Master will look 30.
 * Ripple Hair Attack (波紋ヘア・アタック): The user infuses his Ripple into strands of hair to make them hard enough to block incoming projectiles. Joseph used it to block bullets fired by Santana after ripping a fistful of Stroheim's hair off.
 * Overdrive: Much like any other Overdrive, the technique sends a large pulse of Ripple through an object.
 * Ripple Hypnosis: A Ripple user can hypnotize people by using the Ripple on them. The process can involve a kiss or simply touching the head with the hands. The hypnotized person will act according to the user's demands and be stronger than an ordinary being, being imbued with the Ripple. A Ripple Master can also extract forgotten memories using this technique.
 * Bubble Launcher (シャボンランチャー): The user fires out a barrage of bubbles from their gloves, each coated in the Ripple. This increases the density of the bubbles and allows them to hit objects with a greater impact. When hit by the barrage, a grown man would be completely blown away.
 * Bubble Barrier (シャボンバリアー): Sometimes used in conjunction with Bubble Launcher; the difference is that instead of multiple being used in a barrage, the Ripple user conjures a single gigantic bubble capable of absorbing and trapping its target.
 * Repel: A Ripple user is able to use the Ripple as a repellent of sorts, as well as a shield. The protection is used by Caesar to deflect a high pressured oil jet and later force Esidisi out of Suzi Q's body.
 * Bubble Cutter (シャボン・カッター): Based off the Ripple Cutter, this technique is a direct improvement on the Bubble Launcher, and creates bubbles with the ability to slice. Unlike the original attack, the bubbles spin at high speed and use centrifugal force, but are able to stay intact due to the Ripple. This causes them to form shapes much like saucers with a small blade-like ring surrounding each bubble. These bubbles move at a higher velocity and have a higher tractability, allowing the user to fire them in any direction with ease.
 * Bubble Cutter Gliding (シャボンカッター): A more versatile version of Bubble Cutter, The user sacrifices the quantity of the attack, and focuses on effectiveness. By launching a few bubbles, he is able to aim them much like homing projectiles. They are able to go around objects and have a higher chance of hitting the opponent.
 * Bubble Lenses (シャボン・レンズ): The user produces Ripple-infused bubbles that have the ability to refract light and focus them into beams, much like a magnifying glass. After launching them, the bubbles become stationary and any light source passing through will cause a domino effect, connecting the bubbles together and eventually shooting multiple beams at their target.
 * Rebuff Overdrive: The user charges Ripple into their elbows and delivers a powerful strike.
 * Snake Muffler: A Ripple Master can occasionally use a scarf made with the yarn of an insect called Sathiphorosia Scaraba, which can conduct the Ripple at 100%. The user can send the Ripple through the scarf to stand upside down, leaving the now rigid scarf the only part of the user in contact with the ground. The user may also use the sensitivity of the scarf to detect life signs and know the direction of incoming attacks, even when out of sight.
 * Ripple Overdrive (波紋): The user channels the Ripple into their arm and does a powerful chop attack. This slowly transfers the Ripple blast through the point hit, making it advance until blowing up.
 * Ripple Beat (波紋のビート): The user charges their hand with Ripple and strikes his opponent with a chop.

History
According to Will Anthonio Zeppeli, only one in ten thousand bears the aptitude capable of utilizing Ripple, and the main characteristic of driving Ripple comes from the pressure one has felt through harsh situations in life. Those who are not capable will still be able to use Ripple, but only to an insignificant extent.

Ripple seems to have been created at the dawn of humanity with the purpose of fighting off the Pillar Men's influence on the world along with the vampires and zombies created with their Stone Masks, and stopping them from ever achieving perfection through the Red Stone of Aja. Ripple users have built many devices and temples across the world to help them train and learn from one another.

Similar Phenomena in Steel Ball Run
In the Steel Ball Run canon, a power called the Spin (回転) is introduced, similar in a few notable ways to Ripple; as part of a series of parallels to concepts native to the original canon.

Channeled by Gyro Zeppeli with special Steel Balls and by Johnny Joestar with a Stand power that spins his nails, the Spin enables a range of effects on the environment and the body.

Trivia

 * Araki has mentioned engaging in a morning breathing routine (perhaps like Qigosiming).
 * At the beginning of Thus Spoke Kishibe Rohan - Episode 6: Poaching Seashore, Rohan Kishibe engages in a breathing exercise.


 * According to Araki, the concept of "Rules" and psychic powers in the manga Babel II by Mitsuteru Yokoyama helped him form the basis around the idea of Ripple.
 * The Ripple is similar in concept to the concept of Qi/Ki/Chi, a person's natural fighting energy found in many other manga and anime.
 * The Ripple-based moves, such as the Overdrive, form the basis of some of Joseph's techniques in video game Heritage for the Future, as well as the entirety of Young Joseph's moves. When performing these Ripple moves using the strongest attack button, both Josephs can be seen visibly breathing.