Legend of Qin Ruo
Qin Ruo, the alchemist of the Profound Cloud Continent, was attacked by several opponents when he was about to become one with the pill. His soul managed to escape and possessed the body of the third son of the head of the ancient Qin Clan in Wuzhen's six major families named Qin Ruo. As the son of a big Huaxia family who couldn't cultivate, he was abandoned so as not to bring shame on them. With this body, Qin Ruo would strive to regain his former glory. Anyone on his way would only be a stepping stone.
Once Upon A Time [XXIX]
"Philosopher's Stone: Means 'Sage's Stone'. Also known as: Philosopher's Stone, Heavenly Stone, Great Alchemy Elixir, Red Ultimate Substance, Fifth Entity, etc. Give joy to suffering, and victory to battle , to regenerate the dead, is the promise made by the blood-red stone, which is respectfully called the 'Stone of the Sages'."
This is the entire content of the Sage's Stone in the book "Alchemy Artifacts and Treasures". The English name of the Philosopher's Stone is Philosopher's Stone. Take the first letter of the two words, which happens to be ps. Maybe the ps substance in the diary of the slang refers to the stone of the sage.