How Did I Become an Immortal After Guarding the Abandoned Alchemy Room for Four Years?

Li Xian, a handyman in the outer sect of Dan Shen Sect, is ninety years old and about to die. I thought that my whole life would be like this, but who would have thought that a "system" would come from heaven - as long as I practice, I would be able to gain practice points and improve myself! Overnight, he counterattacked from an old man to the top, and then embarked on the counterattack path of rising through the "hand-rubbed elixir".