I just passed the imperial examination, what the heck is this "Celestial Official System"?

Song Li transmigrated, becoming a newly-passed Taoist scholar in the Great Zhou Dynasty. Initially, he only wanted to survive in this world teeming with demons, lurking immortals, and ruthless ministers. But—what the hell is this Celestial Official System? When you were the Minister of Agriculture, you received blessings from the Divine Farmer Immortal Official. [Sweet Rain Technique] -> [Summoning Wind and Rain] When you were the Construction Official, you received blessings from the Divine Craftsman Immortal Official. [Pavilions and Towers] -> [Blessed Lands and Grottoes] When you were the Imperial Horse Officer, you received blessings from the Divine Steed Immortal Official. [Horse Control] -> [Dragon Subduing]... Many years later. Song Li ascended to the Heavenly Court. When he heard the celestial official wanted him to go to the Imperial Horse Stables, he frowned slightly. "How did I become invincible?"