The version of Kagato featured in Tenchi Universe is distinct from his counterpart in the original Tenchi Muyo! OVA series, representing an alternate interpretation of the character with a different background. In this continuity, Kagato is presented as a rogue member of the Jurai royal family, originating from a branch of the imperial house. He was once a figure of considerable renown, possessing fame, power, and knowledge that were said to rival those of Yosho, the first prince of Jurai who eventually exiled himself on Earth. However, Kagato became corrupted by his obsession with power, specifically the immense might generated by the Royal Trees of Jurai. His rampage was eventually halted by Yosho, after which Kagato was banished to a dimension known as the dark universe. His name and existence were subsequently erased from the official genealogy and history of the Jurai royal family.

In terms of personality, this Kagato is characterized by a deep-seated ambition and a desire to claim the ultimate power of Jurai for himself. He is deceptive and cunning, willing to impersonate Yosho to infiltrate the royal palace and usurp the throne. Once in power, he displays a tyrannical and authoritarian demeanor, ordering the arrest of the true princesses, Ayeka and Sasami, as traitors to further consolidate his rule. His motivations are singularly focused on acquiring and amplifying the power of Jurai. After his exile, he spent his time in the dark universe augmenting Jurai's power with dark energy, which allowed him to return to the normal universe in a rejuvenated, youthful form.

Within the story of Tenchi Universe, Kagato serves as the primary antagonist for the series' second major arc. Upon his return, he impersonates Yosho and takes control of the Royal Tree ship, effectively becoming the false king of Jurai. His role directly places him in opposition to Tenchi Masaki and his companions. He systematically defeats Yosho and Ryoko, demonstrating his overwhelming strength, and kidnaps Ayeka to further his plans. The central conflict culminates in a final confrontation where Tenchi must awaken the true power of Jurai to defeat Kagato.

His key relationships are defined by his opposition to the main characters. He is a direct rival to Yosho, having been defeated and banished by him in the past, and seeks to usurp his identity. He is an adversary to Tenchi, whose latent power he ultimately forces to surface. He also acts as a captor to Princess Ayeka, using her as a pawn. Unlike the OVA version, this Kagato has no direct creator-creation relationship with characters like Washu or Ryoko, as their backstories are different in Tenchi Universe.

Regarding character development, Kagato remains a consistently formidable villain whose threat escalates as he acquires the power of Jurai. His arc concludes with his destruction, as he is overwhelmed and annihilated by Tenchi, who awakens to the true depths of his own Jurai heritage and power. His defeat is final, serving as the climax of that story arc.

Notable abilities for this version of Kagato include his mastery of swordsmanship, making him a formidable combatant even against skilled opponents like Yosho. He possesses the power to control one of Jurai's powerful Royal Tree ships, making him a significant space-faring threat. After augmenting himself with dark universe energy, his power is amplified to terrifying levels, allowing him to easily defeat both Yosho and Ryoko in battle. He is also shown to have regenerative capabilities, as he returned from his earlier defeat in a new, younger body. Kagato's abilities are ultimately rooted in the same Jurai royal bloodline as Tenchi and Yosho, but corrupted and enhanced through external dark forces.