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
Cartoon Network Universe: FusionFall put into the game, where players made their characters and started playing. "FusionFall"'s development, however, stopped so Cartoon Network could focus on other games such as "Project Exonaut", "Formula Cartoon", and "FusionFall Heroes". The Holo Suit, an in-game outfit, used to change look, reflecting in-game events and the time of year. On March 25, 2013, about five months before the original game's shutdown, Cartoon Network released a new "FusionFall" game called "FusionFall Heroes". In this game, instead of playing an avatar players created online, Cartoon Network decided to let online players actually play different variants of their favorite Cartoon Network