The Last Legionary series is a series of five books written by Canadian author Douglas Hill. The books are Young Legionary, Galactic Warlord, Deathwing Over Veynaa, Day of the Starwind and Planet of the Warlord. The series has been described as a simplified version of E. E. Smith's Lensman series.
The books tell of the adventures of Keill Randor, the last survivor of his planet's population, who are annihilated at the beginning of the book Galactic Warlord. Randor's people were hardened over generations by their inhospitable planet, which (combined with rigorous combat and martial arts training) resulted in them exhibiting speed, reflexes, strength, and fighting abilities all at the very upper limit of human ability and Randor himself is one of the most skilled amongst them, twice winner of the planetwide martial arts contest, a feat bettered by only one other legionary in the history of the contest. The people of Moros acted effectively as mercenaries; however they were careful to only offer their services to clients fighting in self-defense. After they are all killed by a mysterious villain known only as the Warlord, Randor vows to avenge them.
A prequel written after the other books in the series, Young Legionary follows Keill Randor through his childhood, from the age of 12 to 18 (within four distinct stories), as he struggles to meet the requirements of becoming a Legionary. The novel also introduces his close friend, Oni Wolda.
As the book begins, Keill Randor is the leader of an off-world Strike Team, far from home. He receives a distress signal from his home planet Moros, stating that they are under attack from unknown forces. Keill's ship has suffered damage, and he is unable to immediately return to Moros. When he arrives, the entire planet is covered with radiation. He is met by Oni's ship, and she tells him to flee the planet; a deadly radiation is killing everyone who comes close to the surface. At the end of Oni's speech, it is revealed that it is an automated message: Oni herself is dead. In grief Keill leaves the planet. He soon realizes that he has still been mortally exposed – the radiation is eating through his body at a slow, though inevitable rate.
Keill begins to search for any fellow Legionnaires who may have survived, relying on his extreme physical conditioning and iron will to fight the course of the disease. His search is fruitless, as it appears he truly is the last Legionary. As Keill begins to lose hope, he is contacted by an unknown agency, but he ignores the contact to pursue some rumors of apparent survivors of Moros. Shortly afterwards, he is attacked outside his ship, and loses consciousness.