Guin Saga

On the run from an army that destroyed their kingdom, the twin heirs to the Parros throne must avoid a magical land filled with incredible dangers. They are surrounded on all sides-by warring armies, an apelike tribe of desert creatures called the Sem, and the ruthless Langon clan. Giant sandworms, glowing, malevolent creatures, and powerful wizards mastering in the dark arts threaten them at every turn. If they were alone, they would surely perish. But in a dark forest, they are discovered by a mysterious stranger, a powerful warrior wearing a cursed leopard mask he cannot remove.