ThunderCats (comics) entered the Book of Omens to begin his training and claim his rightful place as Lord of the ThunderCats, but Mumm-Ra uses a powerful spell to keep Lion-O trapped in the book for several years in real time, not "Book" time, and seizes control of Thundera afterwards. In the follow-up mini-series, "The Return" (written by Gilmore and illustrated by Benes, Pimental and Lea), published in 2003, Lion-O returned to Thundera to find it enslaved to Mumm-Ra. Several of the ThunderCats are scattered. Panthro, who was left in charge while Lion-O was away, was forced into slave labor. Tygra and Cheetara
Cho-Den-O series was to be the first in the Cho-Den-O series. and that the film would feature the cast and characters of "I'm Born!", "Final Countdown", "Kiva", and "Kamen Rider Decade". The first film in the Cho-Den-O series is titled released on May 1, 2009. The film features the return of the Tarōs, Deneb, and Sieg, along with New Den-O from "Final Countdown", Jiro, Ramon, and Riki of "Kiva", and Tsukasa and Natsumi of "Decade". The film also introduces Akina Minami portraying a bushi woman named . The movie also marks the debut of , also called , which appears as a