Warhammer 40K: Where Did the Emperor Go?

The God-Emperor has vanished from the Golden Throne, leaving only a mysterious sphere of light in His place. Liu Bi, an unlucky soul from another world, awakens on a death world where survival means daily gladiatorial combat against nightmarish monsters. His only advantages? An immortal constitution that refuses to let him die, and two adopted sons he's picked up in this grim darkness. In a galaxy where there is only war, even immortality might not be enough.