Sukunahikona

This technique allows the user to instantaneously shrink themselves or any nonliving matter and return it to its original size at will. Because the change in size happens too fast for the human eye to see, it appears as if the objects manifest from nothing when they return to normal size.

Isshiki Ōtsutsuki utilised this jutsu while on the verge of death after being betrayed by Kaguya to enter the body of Jigen, which allowed him to survive as a parasite before taking over his brain.

Isshiki employs this technique in combat by changing the size of his projectile attacks to avoid his enemies from defending against them. He also uses it to dodge enemy attacks and free himself from restraints. He is still able to use Kāma's absorption while shrunk himself. He could also use this defensively against what Kāma cannot absorb, such as reducing natural flames that was burning him.

While inhabiting Jigen’s body, this technique normally required hand gestures in order to shrink foreign matter, but in his original form, Isshiki can do that just by looking at desired objects.

Trivia

 * This technique appears to be inspired by Sukonabikona, the son of a goddess of creation whose name means "small lord of renown", a dwarf no bigger than a thumb.
 * While being controlled by Isshiki Ōtsutsuki, Jigen's body can perform this technique.