Xu Lan reached an agreement with members of the Xu family and inherited the assets. He did so after securing a suitable investor — Song Xi's boyfriend, Zhao Ran.
Xu Lan aspired to be someone like Zhao Ran — someone who looked good in suits and exuded confidence and grace. He signed on the transfer agreement and collected the inheritance from the Public Notary Office. After doing so, he donated the villa on the spot. His charitable act was widely reported on the news.
Subsequently, he visited members of the Xu family with Bai Wu. He planned on liquidating his share of the inheritance by selling it to them. The members of the Xu family were enraged after hearing his intention.
Xu Lan was right. Before he retrieved the inheritance, they were being decent to him. If not for Bai Wu, he might not have made it out alive. He would have either drowned in their saliva or been clawed to death.