Noein is a version of Yuu Gotou from a future dimension known as Shangri-La. Originally a human being, he has transformed into something far beyond ordinary existence, becoming the entity that controls and embodies Shangri-La. His physical appearance is distinct from his other selves, and he possesses a calm, detached demeanor that masks immense power and inner turmoil. Noein's personality is defined by deep contradiction. He retains remnants of his original feelings for Haruka Kaminogi, but those emotions have become warped into a mixture of love and hatred that extends not only toward her but also toward his other selves, including Karasu and the present-day Yuu. His experiences in Shangri-La have stripped him of the ability to fully remember his past, making him fundamentally different from the other versions of Yuu. Noein is driven by a nihilistic worldview. He believes that existence itself is meaningless and that all realities should be collapsed into a single, static point. His primary motivation is to bring Haruka into his timespace in order to end all universes, seeing this as the only logical conclusion to the pain and suffering inherent in existence. This makes him a conceptual force representing entropy, despair, and the annihilation of possibility. In the story, Noein serves as the main antagonist and the ultimate threat behind the conflict between Shangri-La and La'cryma. He orchestrates events from his dimension, sending agents such as Atori, Tobi, and others to capture Haruka. His role is to oppose the Dragon Cavalry and Karasu, who seek to protect Haruka and preserve the multiverse. Noein's most significant relationship is with Haruka, whom he both desires and resents. He is also deeply connected to Karasu and Yuu as different versions of the same person, but he views them as obstacles or incomplete reflections of himself. Unlike Karasu, who grows and changes through his bond with Haruka, Noein remains trapped in his despair, unable to evolve beyond his desire for annihilation. Noein possesses extraordinary abilities derived from his control over Shangri-La and his understanding of timespace. He can manipulate reality across dimensions, teleport, and exert influence over the fabric of existence itself. His power is sufficient to threaten the entire multiverse, and he is able to challenge even the Dragon Cavalry's most skilled members. Noein's development throughout the series is minimal in the sense that he does not undergo a redemption arc or change his core beliefs. Instead, he remains a constant, tragic figure a warning of what Yuu could become if consumed by despair. His presence forces the other characters to confront questions about fate, choice, and the value of their individual realities.