Kukukuiy

As her actions are controlled entirely by her subconscious, Koishi's presence cannot be noticed by other beings unless she allows it, even while standing in plain view because she's closed her mind, or her Third Eye. Likewise her older sister's ability to reading minds cannot read her mind and has no effect on her, as she does not technically have a mind to read; that's why she said, "my sister can't win against me." Even someone who manages to communicate with Koishi will forget about her after she leaves, unless they already knew of her as Satori's sister.
 * Taking actions unconsciously

Some children are immune to this effect due to their still-developing minds, leading Koishi to become their "imaginary friend", though they will forget about her when they grow up.[1] Other than making others unable to perceive her existence, it also makes the act of doing so difficult to perceive. Practically, without being noticed by tengu or the other youkai, she climbed Youkai Mountain. Even the optical camouflage was spoiled.

The youkai satori, on whom she and her older sister are based, by the actions of the humans' unconscious, they saw painful experiences. Due to this it is also not known if this ability was spoken of cynically in the past. However, since she closed her third eye which can read minds, she became unable to read others' minds. As she said herself, "reading people's minds is depressing, there's nothing good about it." She can manipulate the subconsciousness of every living thing around her, allowing her to make them see everything she desires[2] and make them confront their own weaknesses hidden inside their hearts, as seen in lot of her Spell Cards.
 * Manipulation of the Subconscious

Occupation
Koishi currently resides at the Palace of the Earth Spirits, but she is also a laywoman in regards to the Myouren Temple as a recent convert to Buddhism, at Byakuren Hijiri's request.

Possessions
Koishi wanted to receive the blessing of Kanako Yasaka so she could give her own pets power like Satori's pets were given, so Koishi does apparently have pets. During and after the events of Hopeless Masquerade, Koishi now possesses the original Mask of Hope that once belonged to Hata no Kokoro before she lost it. Koishi found it while wandering around Gensokyo, and because of this, she temporarily obtained the emotion of hope.

Suika's ability to manipulate "density" gives her the power to control the density of any given object; to put it simply, assembly and dispersion. As the object's density increases, it heats up, and as it decreases, it turns into a mist.[4] During her spell cards and other attacks, she can also create smaller versions of herself and make herself giant. She can also decrease her own body's density to become a mist, as she did during the events of Immaterial and Missing Power, making it impossible to attack her.[5] By doing this all over Gensokyo, she can effectively keep an eye on everything going on. She can also gather things without shape, like people's souls, which caused the incident in the first place. She has also affected the Moon as reflected in sky (the canopy) to make it explode, then take the falling fragments and turn them into mist as well,[1] but the details as to how are unknown. Youmu Konpaku, after striking her with one of her swords, commented that the sword itself reacted strangely.[6]

With this power, she was able to assemble the thoughts of people and youkai, and made the residents of Gensokyo periodically have a party. Furthermore, with this power she is able to split up into small pieces and become a giant, and she is also able to disperse into the atmosphere. Other than that, she is able to compress her attack and increase her power, and is able to draw the opponent into something like a black hole, and sucking the opponent's power, out of nowhere she assembles rocks and health, and the way she throws it can be seen. It seems like she is able to turn a mountain into sand by this power (according to Immaterial and Missing Power). During her mystery attacks on Myouren Temple in Wild and Horned Hermit chapter 9, she was capable of one-hit knockouts without being seen.

Unbelievably, in her last spell in Immaterial and Missing Power's story mode, "Pandemonium" or "A Million Oni Parade the Night," her spell gauge and her health gauge disperse, making an unthinkable system-intervention model for its usage method.

Possessions

Suika has a gourd that she calls the Ibuki Gourd, which contains a sake bug capable of turning water into sake.[7] To prevent it from overflowing, the gourd has a stopper on it, and she can't pour out more than the gourd will hold at one time