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
Lion (comics) titles of the time. It began to feature an increasing number of anti-hero characters such as The Spider and The Sludge (who would later battle Robot Archie in his own strip). "Lion" merged with several other comics during its life, including "Eagle" in 1969 and "Thunder" in 1971. But by the early 1970s sales were slipping, and in 1974 it was merged with "Valiant". Several strips continued in "Valiant", but that title merged with "Battle Picture Weekly" in 1976. In 2005 many of IPC's characters, including several from "Lion", were featured in a mini-series called "Albion" published by the WildStorm