Yū Godai and Mako Oikawa’s The Ancient Magus’ Bride – Psalm 75: Lightning Jack and the Fairy Incident (Mahō Tsukai no Yome Shihen.75: Inazuma Jack to Yōsei Jiken) spin-off manga has announced on the Manga Doa app that the manga will go on hiatus due to Oikawa suffering from an illness. The app and its official Twitter account will announce when the manga will resume at a later date.
The story of the manga is described as:
Faerie-born Jack Flash and her human-born brother, Larry, run a detective agency in New York City specializing in crimes committed in the hazy boundary between the human and faerie realms. They never expected to receive a letter from an ancient magus of the Old World, but Echos, caretaker of dragons, has a task for them.
Godai and Oikawa launched The Ancient Magus’ Bride – Psalm 75: Lightning Jack and the Fairy Incident in Manga Doa in April 2019. Seven Seas Entertainment is publishing the manga in English.