Bai Xiao did not intend to hide the truth about their children.
"Actually, your mother didn't die in the chaos caused by the refugees of the Five Nations back then. Instead, she was forcefully brought back to the clouds from the Five Countries by someone using a formation."
The matter started with Yun Yin's identity.
Yun Yin was the sister of the sect master of the Celestial Sect, the largest immortal sect. She was also one of the elders of the Sky Sect.
She was born with precognition.
Because of this, she was able to help her elder brother, who was the sect master, make the Celestial Sect stronger.
Originally, she should have continued as an elder in the Celestial Sect. Then, through cultivation, she would have become a Celestial Lord.
But an unexpected prediction had shattered her peaceful life.