Shushan Qi Xian Lu

Zhang Gong is a little apprentice pharmacist from Mount Shu. One day he entered the mountain to gather herbs and met an Immortal Hero who was slaying a demon. He accidentally got involved in a demonic battle. After going through a soul-stirring adventure, he finds out about his hidden background, and thus becomes embroiled in the strife of the Three Realms.

(Source: MangaToon)