Mirage of Blaze

The generals during the Warring State Period that passed away without unifying the country have waken from death as vengeful spirits and turned the world into a "Darkness Warring Country". Fighting the "Darkness Warring Country", underworld Uesugi had the most powerful "FORCE" and purified the bad spirits and sent the spirits to the underworld. A boy named Takaya Oogi is told by Naoe at one incident that he is actually Kagetora Uesugi, the head leader of Uesugi Underworld Army... (Source: Aniplex)

Ogre Slayer

There was once an ogre (oni) mother who gave birth to human looking child. Instead of an ogre`s horn, this child was born with a sword in hand called the "Onigirimaru" or Ogre Slayer. He has no name and is only refered to by the name of his sword. Though he appears human, he is pure ogre. Believing that he will become human once all of his kind vanished fromthe world of humans, he sets out on his destiny to slay all of his kind. Even now, in the mother world of Japan, he is still out there slaying ogres. Description from ANN