Several months ago.
Chu Ning had asked Lin Nan to help him find a female cultivator.
In describing this female cultivator to Lin Nan, Chu Ning gave the following details: she loves wearing red dresses, her cultivation is at the Divine Transformation Mid Stage, but it's also possible that she's reached the Divine Transformation Late Stage, and she has delicate features.
As for why he wanted to find this female cultivator, Chu Ning's reason was that when he first entered the Cangtian Realm, due to some accidents, he suffered a spatial storm and became weak. This female cultivator saved him.
She had only placed him in a safe area and left some elixirs behind before she departed.
Because he was weak at the time, he couldn't determine whether the woman in the red dress was at the Divine Transformation Mid Stage or Late Stage.
He didn't know her name, nor her origin.
He wanted to find this female cultivator to express his gratitude for saving his life.
