- "You call your power religious devotion. I call it "Ki". It's the same thing."
- —Gouken to Dhalsim, Super Street Fighter IV
Ki is a preternatural and esoteric form of energy that is said to be found in all things. Within living beings, ki can be wielded and harnessed via martial arts and other forms of physical activity, as well as specific exercises. Ki can also be quantified as the strength and build of one's body, along with health, finesse, and muscle.
Many fighters in the series are seen wielding this power in their attacks, manifesting in projectiles and attack moves that are engulfed in energy.
Ki can take on a neutral form of energy, but as mentioned in the backstory of Urien, it is said that the user's own ki can take on elements one is more sympathetic with; as such, various elemental energies like flame and electricity are seen. It is noted that, according to the Illuminati, they believe the maximum number of elements one could manipulate is three (not including Light and Darkness, since they aren't specifically elements), as demonstrated by their Sixty-Six arts.
According to supplementary materials, its temperature throughout the series is also said to vary upon one's disposition and internal motives as well, regardless of one's manifestations; those who are motivated by negative emotions such as Akuma are said to have cold ki, those who fight with extroverted passion and a sense of justice like Chun-Li are said to have lukewarm ki, those who fight for the sake of improvement and justifying their need for combat like Oro are said to have warm ki, and those who use Psycho Power are said to have blazing hot ki, ironically due to how the negative ki redirected but without anywhere to direct itself to manifest by the Psycho Drive's mechanics, becomes extremely erratic due to it being stored.
Throughout later series, especially in Street Fighter IV and Street Fighter V, ki is often depicted in the ink like motions and waves thematically seen in visuals. The new mechanic featured in SFV, the V-Trigger, is likely a new mechanic focusing on how one's ki manifests when they fight at their fullest state.
Oro believes that all forms of ki ultimately come from a universal source, and that their various manifestations are simply alternate methods to breaking physical limits and obtaining more power. As such, Psycho Power and the Satsui no Hado are not inherently evil powers, rather they are used maliciously by people to cross their normal boundaries. Oro's knowledge of ki allows him to even utilize the Satsui no Hado, albeit only to demonstrate it to Dhalsim.
Character Ki Manifestations
- Ryu: Light, Wind, Fire, Electricity, Satsui no Hado and Power of Nothingness - The first time Ryu used elemental properties on his moves was in Super Street Fighter II's Shakunetsu Hadouken. Although it was not until Street Fighter III that Ryu gained an official affinity, he was given the electrical element in its fullest form in the lighthearted parody series Super Gem Fighter Mini Mix. He mainly manifests this through the Denjin Hadoken; Street Fighter V gives him the V-Trigger Denjin Renki, which charges his fists with a static aura. To a lesser extent, his ki has also shown to manifest in various other varieties. His ki is considered naturally warm.
- Ken: Light, Electricity and Fire - Ken can be considered the one of the first to have a manifestation series wise, seeing it manifest in his variation of the Shoryuken and the Shoryureppa. Crossover series depict this varied, but the Marvel vs. Capcom games sees his a greater majority of all his super attacks burst into flames. In Street Fighter X Tekken, his Shippu Jinraikyaku is imbued by lightnings.
- Violent Ken: Darkness, Fire and Psycho Power.
- Chun-Li: Light, Wind and Water - Her ki has always manifested at its most basic form, and as a flowing light blue energy. Her Renkiko V-Trigger's dynamics subtly acts akin to water in motion.
- Sodom: Fire
- Dhalsim: Faith and Fire - Though his training and grasp of spiritual metaphysics lie in that of another school, Gouken reveals a bit of interconnected truth in how Yoga and the concepts of prana, chakra, and kundalini share traits with the thought of ki. Though his flames are perceived as real, they are the result of spiritual works in that they are real if one thinks them to truly be.
- Cammy: Psycho Power - In some of the versus games, certain moves of Cammy's put a blue-flame particle effect on the opponent. It is presumed that this energy is Psycho Power due to her connection to the Dolls and therefore M. Bison.
- Sakura: Light and Electricity.
- Sean: Light.
- Alex: Light.
- Guile: Wind and Light.
- Sagat: Light and Fire - Like Ken, Sagat's ki can manifest into fire with his attacks, most notably his Tiger Shots (though Tiger Raid and Tiger Rampage are the only ones that actually sets the opponent on fire). This is due to Sagat's dedication to improving himself, likely making his ki warm.
- Dee Jay: Sound and Wind - With his love of fighting and dance, he is physically fit to both dance and thrash about. His Air Slasher is also said to move at the rate of the speed of sound, literally carrying whatever noise and audial media happens to be made in his surroundings, and amplifies it on contact to his target. His ki is considered lukewarm due to his love of fighting.
- M. Bison: Darkness, Fire and Psycho Power - Bison's ki has been considered to be blazing hot, due to its correlation with Psycho Power, which requires one to purge all good and light in order to amplify its power with negative emotions. Bison's grasp of Psycho Power is so strong, that it even threatens the stability of his own manifestation, thus requiring him the need of spare bodies (other people) to contain his powers.
- Blanka: Electricity.
- Goutetsu: Light, Dark and Satsui no Hado - Gouken and Akuma's master, Goutetsu was able to use the Satsui no Hado without giving in to its darker side before his death at the hands of Akuma.
- Fei Long: Fire.
- Cody: Wind.
- F.A.N.G: Poison.
- Phantom: Poison - As F.A.N.G's apprentice after the events of Street Fighter V, it is likely she can (or at least will) be able to manipulate poison as well.
- Abel: Wind.
- Poison: Light and Electricity.
- Balrog: Wind.
- Zangief: Light.
- Rashid: Wind.
- T. Hawk: Wind and Earth.
- Laura: Electricity.
- Ibuki: Light, possibly fire due to coloring differences between Raida and Yoroitoshi, and possibly wind due to Kasumi Gake and Kazegiri.
- Dudley: Wind.
- Dan: Light.
- Go Hibiki: Light and Satsui no Hado - Whereas he only makes an appearance in the non-canon Super Gem Fighter Mini Mix, in that game he does use this ki whenever Dan summons him.
- Rose: Soul Power.
- Ingrid: Light and Soul Power.
- Remy: Light - His wielding of light based ki is rather unique, in that his disposition, being cool, and hence negative, has also seemingly melded into his own flow. It appears as an icy aqua and white ki.
- Yun: Wind.
- Yang: Light and Wind.
- Gen: Wind, Power of Nothingness and Satsui no Hado - Gen is the only known character that welds such powers of both light and dark balanced, due to the nature of his martial art styles (Mantis and Crane) used by him, which was based off his experiences as an assassin.
- Oro: Light and Jindan - Having mastered Senjutsu, the dynamics which dictate ki and are studied deeply by the martial art are refined greatly to balanced but potent proportions. This in turn creates what is known in Taoist lore as Jindan, being the literal golden elixir said to bring about immortality and legendary powers attributed to Xian. Oro has attained Jindan within his being, and his abilities are nevertheless showcased; from superhuman strength to his limits to give his opponents a fighting chance. Manifesting as light is likely his choice of preference, as he can even manifest an imitation of the Satsui no Hado.
- Makoto: Dantian - (v.i.a. Tanden Renki; Tanden Renki's Japanese name translates to Dantian Refined Spirit: Form of Offense. Dantain are also known as the Qi Focus Flow Centers, important focus points for Qigong and many martial arts).
- Gouken: Light, Electricity, Chikara no Hado and Power of Nothingness.
- Akuma: Darkness, Fire, Electricity and Satsui no Hado.
- Necalli: Darkness and Earth.
- Urien: Earth, Metal and Electricity.
- Q: Fire - The only move of Q's that can be confirmed to use ki is Total Destruction, which includes a fiery explosion.
- Gill: Light, Cold and Fire.
- Twelve: Any - The form of ki Twelve uses depends on the fighter he is mimicking v.i.a. X.C.O.P.Y.; he cannot wield ki by his own power, only with this ability.
- Juri: Light and Darkness.
- Kolin: Cold.
- Ed: Darkness and Psycho Power.
- Menat: Soul Power.
- Falke: Darkness and Psycho Power.