The Bankai of Tekiro Kuchiki, it is said that it is one of the most powerful Bankai's to ever be seen in the history of the Soul Society. With a sheer raw power of lightning, giving Tekiro undetectable speed, and the ability to control the sky, along with being able to generate his own lightning, it truely is a powerful Bankai indeed.
While in Bankai state, Tekiro can use all of his Shikai abilities, as well as:
Summon: Tekiro may summon a manifestation of his Bankai to fight for me. Tekiro's Bankai manifestation looks very different to his Shikai's manifestation.
Enerugi no yūgō, Inazuma Nakagami (エネルギの融合, Literally Meaning "Fusion of Energy").
Tekiro conjures a massive ball of lightning, that instantly seeks it's target and strikes it with a massive force, leaving an orb of raw energy around the target burning them for a short duration.
Inazuma no hyōji, Inazuma Nakagami Shi no arashi (稲妻の表示, Literally meaning "Display of Lightning").
Tekiro's most devastating attack, he takes control of the skys, creating a deadly super cell lightning storm, 10x stronger then normal lightning, this lightning can kill anyone on impact. Using this ability completely depletes Tekiro of all spiritual pressure, rendering him useless in the battlefield until he has had 3 days to recover.