Bai Yunlai is an alchemist of the Violet Fate Sect's East Pill Division who befriends Meng Hao when he first joins the Sect under his Fang Mu persona. He guides him about the Violet Fate Sect and helps him to grow his reputation. As Meng Hao's reputation and skill grows, their relationship grows more distant.
Bai Yunlai had an ordinary talent in alchemy, unlike Meng Hao and as Meng Hao's status kept improving he felt he wasn't worthy to be Meng Hao's friend. Instead, he thought of himself as more of a subordinate. This caused Meng Hao to be sad, but he knew that there was no way he could force their relationship.
During the Ancient Dao Lakes Erruption, Bai Yunlai reluctantly goes to meet Meng Hao, as he was unsure whether Meng Hao still remembered him or not. Of course, Meng Hao was delighted to see him as he always thought of Bai Yunlai as a close friend.
It is unknown whether Bai Yunlai ever managed to become an alchemist or not.