Star of the Guardians is a series of four science fiction/space opera novels written by Margaret Weis without assistance from usual co-author Tracy Hickman. The original trilogy, The Lost King, King's Test, and King's Sacrifice, concerns Dion's adventures and eventual rise to the throne. A few years later, Margaret Weis realized that, while Dion had achieved his goals, the main characters of the series (sundered lovers Sagan and Maigrey) had not achieved peace, and penned the fourth book, Ghost Legion. She has since completed a trilogy of spin-offs concerning the mercenary team Mag Force 7 introduced in King's Sacrifice. Based originally on The Magnificent Seven, the team developed a much more varied membership just in time to star in their own novels: The Knights of the Black Earth, Robot Blues, and Hung Out. Weis and Don Perrin released a collectible card game under the name Mag Force 7. Source: Wikipedia (en)