Twilight Ninja Underworld Tomb

Two friends…One only wanting power… The two trained under the same master for many years.Later he would make a pack, breaking the old seal.Releasing the greatest demon the world has ever faced!With this new found power, he overpowered their master!Then he bonds a sword to his friends back!Telling him, the only way to remove it is to kill me! Many years pass and the boy trained, becoming a true ninja! Now his true quest will begin!