Lao Liu Cultivates Immortality, and the Heroine Takes All

Do the old six behaviors, accumulate, and redeem special skills (such as: enhanced version of stealth "I'm just a tree"). The protagonist uses modern chemistry knowledge to improve the elixir recipe ("Extraction method to refine the body tempering elixir, purity 99%"). Serious exploration is prohibited in the secret realm, and frivolous operations are encouraged. Look at Lao Liu's cool moves.