Nankaina

Nankaina (難解な, meaning esoteric) are unknown beings that was said to have exist outside Soul Society, Hueco Mundo and the World of the Living. They're purpose was to "restart" all of existance by eliminating all life in all worlds, which will ultimately include themselves when all is said and done.

Physiology
Nankainas are unknown beings. Though they have a humanoid body similar to Shinigami, their reiatsu are completely undetectable. According Rukia, they're so mysterious that when she tries to sense their reiatsu even while in front of them, she does not sense any, as if they're not there. Even Yumichika, who tried absorbing their reiatsu, was left defenseless.

They are so mysterious that they describe themselves as "not alive nor dead and simply exist."

History
Not much is known about them. They first appeared in The Untold Chapter: Nankaina tai Shinigami. They attacked Soul Society, almost immidiately charging toward to the Captain Commander Yamamoto. Though the old man defeated them with little to no effort, they simply attacked as a distraction.

During their attack on Gotei 13, they were sent to attack Karakura Town. But their plans were thwarted by Ichigo and his friends. During their battle with the Nankaina, Uryu managed to capture one. However, when he ask what they were doing there, the enemy simply tells him that "Peace is at hand" then disappears out of thin air.

To be continued...

Combat

 * Hakuda: (白打, meaning white hits) Nankaina are skilled in Hakuda, an unarmed fighting technique that makes use of one's own body in a fight. They were so skilled, they defeated Onmitsukidō with ease but were defeated by Suì-Fēng. Even she was surpirsed that these beings are able to use this fighting style.
 * Ginga ho: (銀河 歩, meaning galaxy step) Nankaina have the ability to move between dimensions and appear back to the same dimension at will. They can use this ability to also interact with something in another dimension (for example stairs) while staying in the regular dimension. Urahara states that this technique makes Shunpo, Sonido and Hirenkyaku look slow. This is the same ability that they use when traveling to their dimension and Soul Society or the World of the Living.Esoterica_003.png
 * Genshi Kaminari: (アトム雷, meaning atom lightning) This technique allows them to create ball of lightning to blast at their opponents. These balls are strong enough to destroy a Danku without incantation. Like the Nankaina themselves, these balls are undetectable if one tries to search its reiatsu.
 * Reiatsu absorption: This unnamed technique allows them to absorb the reiatsu. Though they cannot absorb directly from a Shinigami or Quincy's body, they can abosrb the projectiles they create, such as Ichigo's Getsuga or Uryū's Licht Regen.Nankaina_004.png

Trivia
Work In Progress.