The 'Life-regenerating Elixir' was first made by an immortal Zhenren of Qing Xuan who specializes in the Dao of Elixir. It took him a lot of time and spiritual ingredients to prepare just one full oven of it. The elixir was in defiance of nature as it could rejuvenate broken limbs to rebuild a body.
After so many years, there were only three of it left.
Shen Lian generously wanted to give two of it to two of his disciples, and that shook Hong Qianya to the core.
He tried to stop Shen Lian as the elixir was considered precious. What if an emergency happened in the future and they ran out of it?