The series adapts Scott Westerfeld's Leviathan trilogy (Leviathan, Behemoth, Goliath), published between 2009 and 2011, with each novel adapted as a four-episode arc.

The anime adaptation was announced in June 2024, with a teaser trailer released in September 2024, ahead of its global Netflix premiere on July 10, 2025.

The series is directed by Christophe Ferreira and produced by Qubic Pictures and Orange, blending alternate WWI history with steampunk and dieselpunk science fiction elements.

The opening theme 'Paths Combine' and closing theme 'The Sky Ahead' were composed and performed by renowned composer Joe Hisaishi, with the closing theme featuring vocalist Diana Garnet, while the series' score was composed by Nobuko Toda and Kazuma Jinnouchi.

IGN's Kristen Carey praised the series as a potential 'modern classic', comparing its animation and setting to the work of Studio Ghibli.

Critics highlighted the explicitly queer characterization of protagonist Deryn/Dylan Sharp, who chooses to maintain a more masculine identity even after their assigned gender is revealed later in the series.

Reviews were mixed to positive: Gizmodo called the anime 'imperfect' with animation that 'may occasionally falter' but still praised it for rising above its visual shortcomings, while Polygon and Ready Steady Cut criticized its young adult tone and underuse of the premise.

Russian outlet Mir Fantastiki felt the adaptation lacked 'the craziness that made the book so appealing' but still called it 'heartfelt and engaging' and largely faithful to the source material.