If what Lu Ye says is true, then it truly concerns the survival of the Nine Provinces. As Lu Ye elaborated, the Blood Refinement World is a domain not inferior to the Nine Provinces, and the blood clan ruling this domain treats the human race as Blood Food. In the ideology of the blood clan, humans are the livestock they breed, to be taken and used at will. Once such a domain comes into contact with the Nine Provinces, it would inevitably end in an endless confrontation, leaving no chance for fortune.
But such significant matters naturally cannot rely solely on Lu Ye's words to be believed; some convincing evidence must be presented.
The best would be to let them enter the Blood Refinement World now and witness it themselves.
Of course, Lu Ye cannot achieve such a feat; he himself cannot enter the Blood Refinement World at the moment, but he has other preparations.
