Sekiei

Sekiei looks like a pale young man with a brown bowl cut and wide, green, pupil-less eyes. Bandages mask him from the nose down and also wrap his hands, and he wears a purple tunic pulled over a black bodysuit.

Sekiei comes across as childlike and easygoing, forever doodling and speaking his mind without a filter. He writes humans off as the weaker kind, yet their feelings and the way they bond fascinate him all the same. Of all the fabrications he feels the most, grieving openly for Kakō and Kokuyō and describing a 'pain' inside though nothing has wounded him. He gives his trust and loyalty fully, the only one of his kind to embrace Mitsuki outright, which makes the shock of Mitsuki's supposed betrayal cut all the deeper and rouse a rare fury in him. What he wants, above everything, is to be tied to other people, for those bonds are what give his life meaning.

Made with jutsu of his own, Sekiei carries implanted Explosive Clay, letting him pair Earth with Lightning Release to produce Explosion Release; through the C1 kekkei genkai he shapes clay bugs that burst apart.

He first turns up at Konoha's gate backing Kokuyō, downing Saō and Uō before slipping away with Mitsuki. When the illusion over Yurito lifts, his C1 goes off and leaves the man barely alive. On the road toward the Land of Earth he warms to Mitsuki, an artificial human like himself, only for Kokuyō to cut short his talk out of distrust. Pursued by Leaf ninja, he is sent ahead while Kokuyō stalls them, then squares off against Sarada Uchiha and Boruto Uzumaki, whose devotion to their friend intrigues him even as he tries to kill them. His clay proves overwhelming until Boruto calls up Garaga, and when Sekiei's body suddenly fails, Mitsuki arrives to save him and cements his place among the fabrications by cutting Boruto down with Lightning Release.

As his condition worsens again, Mitsuki keeps watch, and Sekiei snares him with a clay insect, having guessed that the guard's death back in Konoha was faked. Mitsuki explains he only left a note about choosing to leave the village, and Sekiei chooses to hide that message as a token of friendship. Back at the base, a scientist studying Mitsuki turns up a cursed mark set upon his heart. Around that time Kirara weakens, her genjutsu over the village elders collapses, and Kū seizes power, refusing the heart transplants the fabrications crave without Ōnoki's leave. They hunt down Ōnoki, who will not consent, so Kū subdues him. Sekiei, breaking down once more, tells the doctor he wishes only to guard his friends, and Mitsuki warns that owning a heart makes no one human. Delivering a finished heart to Kū, Sekiei watches Mitsuki's betrayal, the heart revealed as disguised snakes, and stays behind to face him in a rage, hurling clay even as his body gives out. Mitsuki insists the friendship was real and offers to carry him to Orochimaru for repairs; conceding at last, Sekiei holds out his fist for a final bump but dies before Mitsuki can answer it.