Douglas Hill 
Galactic Warlord 

He stands alone, his planet, Moros, destroyed by unknown forces. His one vow – to wreak a terrible vengeance on the sinister enemy.But Keill Randor, the Last Legionary, cannot conceive the evil force he will unleash in his crusade against the Warlord, the master of destruction, and his murderous army, the Deathwing.