Wu Hen wasn't completely clueless about his host's background.
He realized that although his second sister, Cai Lan, was not an illegitimate child, her status in the family wasn't high.
Most likely oppressed and scorned by their father, Master Cai Huang, in the past, now, according to what Cai Ni said, it seemed that Cai Lan had transformed from a sparrow to a phoenix, holding a high position in the entire Holy Sect.
Combining this with the fact that Master Cai Huang had been exiled to this godforsaken place, Wu Hen suddenly understood.
That's why Master Cai Huang, this Old Deng, had suddenly become so tolerant towards him, even giving him such a lucrative job. It turned out he was counting on him to cling to his newly successful second sister, Cai Lan!
As the saying goes, when one man attains Dao, his pets ascend to heaven, Cai Lan probably felt no affection for her father and other siblings, only harboring some fondness for her brother who was also scorned.