Ripple

Ripple (波紋), also known as Sendō (仙道), is an ancient form of martial arts.

Through self-controlled respiration, Ripple links trained persons with 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 Part II: Battle Tendency. It is also briefly featured in Stardust Crusaders.

Description
Ripple is based on using the energy of the sun's rays through breathing and empowering the body with "ripples" of solar energy. While it can be used to destroy vampires and zombies, it can also affect non-living things. An object, while charged with Ripple energy, will become more dangerous, and its user can perform several techniques that can combine with the warrior's own tactics, to allow for a very flexible fighting style.

Ordinary humans can also be affected by Ripple attacks, as Caesar had used his Ripple to control a woman into fighting Joseph before he had undergone the final stages of his training, and Joseph's trained Ripple would have caused an ordinary person experience a pins and needles-feeling before fainting - similar in nature to symptoms experienced after prolonged exposure to the sun's rays. Kars' Ripple energy, boasting several hundred times Joseph's power, caused Joseph's flesh to nearly instantly melt. Ripple is also transferable between users, as both Will A. Zeppeli and his grandson Caesar transferred their Ripple to the protagonists they were aiding shortly before their deaths. Ripple users can reject harmful substances inside of them by ejecting it from their bloodstream with the use of Hamon energy.

Because of its versatile nature, many warriors use different weapons ranging from a scarf, bubbles, wine, and even Clackers (in this case a pair of steel balls connected to a rope). 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 Hamon energy through it, and will become lethal to the 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.

Liquids conduct Ripple especially well (and the user's Hamon shows on liquids as actual ripples), and it can even be used to increase the surface tension enough to allow the user to walk on water. It was mentioned by Joseph that objects covered in oil can conduct Hamon much easier. Joseph was also shown to be able to cover his body in Hamon energy by channeling through his own Stand. It is unknown if a humanoid Stand like Star Platinum, belonging to his grandson Jotaro, could do the same.

Weaknesses
While the Ripple users can make even the most simplistic of objects into lethal weapons and become themselves dangerously powerful, 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 Ripple. Dio had also discovered that he could flash-freeze a Hamon 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.

Techniques
Note: due to the versatility of the Ripple and the near universal ways of deploying it, there are few shared techniques and Ripple Users will have their own personal techniques as opposed to standard attacks. Most of the Attacks here are shown to be exclusively used by one person, and the list doesn't include every way to use the Ripple
 * Forced Ripple Breathing (強制波紋呼吸): The Ripple user gut punches someone with the little finger raised so he reaches one's diaphragm. By doing so the target will momentarily lose their breathe 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. 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 wine 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.
 * Sendo Wave Kick (仙道): A ripple-infused strike with the knee. The ripple energy tears vampires and Undead 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 detects others even through walls.
 * Sendo 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.
 * 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 rapid flurry of Ripple-infused punches with power comparable to the sun itself and has the ability to completely obliterate the Undead.
 * 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 transfers 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.
 * 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 years old Ripple Master will look 50, while a 50 years 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. He used it to block bullets fired by Santana after ripping 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 man, 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 his gloves, each coated in the Ripple. This increases the density of the bubbles and are able to hit objects with a greater impact. When hit by the barrage, a grown man is 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 able to deflect a high pressured oil jet.
 * Bubble Cutter (シャボン・カッター): Based off the Hamon Cutter, this technique is a direct imporvement on the ubble Launcher, and creates bubbles with the ability to slice. Unlike his 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 Caesar 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 bubbles 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 his 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 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. He 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 his 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 his 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 Hamon comes from the pressure one has felt through harsh situations in life. Those who are not capable will still be able to use Hamon, but only to an insignificant extent.

Hamon seems to have been created at the dawn of humanity with the purpose of fighting off the Pillar Men's influence on the world. This also includes the creation of minor demi-humans, known as vampires and zombies, created through the 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 Part VII
In the new canon beginning with Steel Ball Run, 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 Rohan Kishibe - Episode 6: Poaching Reef, 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 Hamon.
 * The English dub of the OVA translates Ripple as "Wave Energy."
 * Hamon is similar in concept to the concept of Qi found in other manga and anime.
 * 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.
 * Ripple also has medicinal usages, such as being use to effectively counter and reverse gangrene.