Immortality Martial Arts: Starting from Reversing the Cost of Cultivation

[Blood Burning Knife Technique: Every time you swing a knife, your life will be reduced by 1 year. The price of practice is reversed... [Blood Burning Knife Technique: Every time a knife is swung, life will be increased by one year. ... [Longevity Fist: Practicing this method can increase the upper limit of one's lifespan. The price of practice is reversed... [Longevity Boxing: Every time you practice it, your life span will be reduced by 1 year. Lu Yuan, who unexpectedly came to the fantasy world, gained the ability to reverse the cost of practice, so he practiced those forbidden arts crazily. Any martial arts that would cause great harm to himself was a treasure in his eyes.