TV-Series
Description
Zett Takajō (alternately spelled Zed Takajō or Zeta Takajo) emerges as a recurring presence throughout multiple Devil Children narratives. He first appears as a human boy characterized by teal spiky hair featuring a small braid, tanned skin, and amber eyes. His signature attire includes a dark blue aviator hat with gold trim and spikes, a blue sleeveless shirt embroidered with jagged patterns and an evil grin motif, a black undershirt extending into fingerless gloves, blue shorts, and black leather boots.

Within the Shin Megami Tensei: Devil Children anime, Zett frequently confronts protagonists Setsuna Kai and Mirai Kaname in Harajuku, transporting them to the demon world (Makai/Expanse). He offers crucial guidance throughout their journeys, intervening at pivotal moments such as Setsuna's quest for his kidnapped brother Nagahisa or Mirai's search for her missing father. Zett supplies essential items like the Messiah Horns/Eyes to aid their progress across Makai's diverse realms.

A pivotal revelation unfolds in the Deep Hole bonus dungeon. Following Zebul's defeat, Zett discloses his true identity as that entity, explaining his orchestration of events to fulfill Lucifer's objective: activating the Ragnarok program. This outcome positions him as a Chessmaster, manipulating conflicts between angels and demons to avert Armageddon while accepting uncertainty about the new world's future. His motivations include observing the coexistence of humans and demons post-Ragnarok.

In Devil Children: White Book, Zett similarly guides Masaki Kuzuha into the Expanse to find a cure for the cursed Shou Ougi, directing him to a portal at a construction site, maintaining his role as the quest's initiator.

The manga adaptation reimagines Zett's origin and relationships. Here, he is portrayed as a childhood friend of Setsuna and Mirai, created by the primordial deity Hoshigami to oversee the human world with minimal interference. His awakening to his true identity as Zebul intertwines with the destruction of Fire Land, caused by the Deep Hole's formation as a dimensional void, emphasizing personal connections prior to his transformation.

Across all media, Zett consistently embodies mystery and manipulation, delivering exposition or strategic advice. His actions perpetually drive the central plots involving interdimensional travel and cosmic conflicts between demonic and angelic forces.