This series is getting complicated:
to recap

Zero is dead, but is resurected as the new God of Death? But myserious new villians based on Kurohime's past have appeared to kill her. Also evil Zero wants to kill her too? So Kurohime is traveling back in time to try to understand Zero who she doesn't know much about inside the stomach of the time eating sea-dragon - thnk i got it all 🤣