Chiyou's Demon Blade

Lu Qingyun is an orphan from a poor mountain village, with no one to rely on. He lives with an old man who is not his grandfather, though Lu Qingyun calls him Grandpa. One day, while gathering firewood, he encounters a snake and flees to a cave, where he comes across an ancient divine weapon: the Chiyou Demon Saber. Lu Qingyun accidentally gets his blood on the saber, and the two become connected in spirit. He can control the weapon as if it were part of his body. It can even change size, shrinking small enough to hide, since such a precious treasure must not be discovered by everyone. And so, he begins his rise from the bottom.