A young prince returns to kill undead who destroyed his homeworld, in the futuristic age where it advanced beyond his knowledge. In the world where transport between dimension had became more open but expensive. Seirule Steiner's life flipped when the kingdom he didn't yet rule, Bluechard, shocked with self-regenerated enemy. Escaped to Tenth World from Undead War, he had been researching undead's weakness alone ever since very young age. All for beating Dyfolt, the traitor of humanity, Undead King. However, Dyfolt wasn't stupid as it appeared, portrayed skill as the wisely in Bluechard, continued sending undeads to hunt and erase Seirule, the only one who knew the secret of Perfect Blueprint. After long of hardship, ten years, he readied to kill his uncle when arrived back to First World. Unfortunately, his homeworld wasn't forgivable as it seemed. Seirule couldn't overthrow Dyfolt who had new and complex technology. Thus halted Conquer Plan despite found Undead's weakness, Seirule who grew in medieval age had to rebuild strategy from zero, in futuristic age.