Tenkuu Tenkuu no Mi

The Sei Sei no Mi (精精の実, "Aether Aether Fruit") is a Logia-type Devil Fruit that was consumed by Gai Nagareboshi. It allows the user to create, control, and become aether, which is also spelled æther or ether, the material that fills the region of the universe above the terrestrial sphere. Aether is the fifth classical element after earth, fire, water, and air.

Strengths and Weaknesses
The Sei Sei no Mi is known as the "Devil Fruit by which aether, the fifth essence of the universe, flows," in reference to how aether's natural form is a divider between spaces of the universe. By using this ability, Gai can emit aether in its most natural form causing air space or matter to split and eliminate natural forces. Gai can also focus aether in a way that it takes a physical essence, appearing like pure energy. From there, the energy can take on a variety of functions.

This Fruit has the usual Devil Fruit weaknesses, though for some reason, the user takes double the damage from Haki than usual, and if struck with Bushoku Haki, they are unable to utilize the Fruit's ability for a brief moment.

Usage
The techniques aren't just limited to the physical, as Gai has shown that he can create "voids" in an enemy's harnessing of their Haki, though this is temporary, as Gai can delay the Haki for the briefest of moments, though stronger iterations of Haki can bypass this ability entirely. As a supplement, Gai can eliminate the adverse effects of the earth's natural forces upon himself in order to move more freely, the concept being used in one of his techniques as aether flows from Gai's eyes being the source, to void him of the limits created by outside forces. This ability is also able to allow Gai to absorb aether from around him, to a small extent, to gradually accelerate healing. Gai's mastery with this fruit allows him to utilize aether attacks with powerful aftereffects to quickly gain an advantage. Gai also uses several trick abilities with this fruit to protect himself from being hampered and negated so he can continue his onslaught.