Under the Underworld: My Sword and I Can Hold the Sky Down

Friends, are you cultivating immortality? There is no manipulation at all, just implant the evil bone into your body and you will have your spiritual roots opened. What? Do you think the death rate among cultivators is high? There are some, and we can still practice martial arts. Take one of your own bones and implant it into the body of an alien animal for nourishment. When it matures, take it out and implant it into yourself again. You will have successfully laid the foundation of martial arts. You will use your bones to nourish your blood and become stronger than ever. What? Are you saying that martial arts is not normal? There's nothing we can do about it, brother, after all, this is hell here! If you don't want to be eaten, then practice!