Give them a beating first without giving any warning… and then threaten them.
Wang Hu believed that, with this method, there would be few Transformation Realm beings from other species that could refuse.
The reason was simple. For most species on Earth, they didn't have a strong sense of concept about species.
Or rather, instead of saying that they didn't have a concept of species, it should be said that it wasn't strong—not to the extent of choosing to die rather than being subordinate to another species.
They were born only to survive and reproduce.
Even if their human intelligence were activated, it did not change. They wouldn't suddenly develop the strong notion of 'creatures of other species must have opposing interests'.
They believed more strongly in the law of nature where the strong were respected—they should survive and listen to the strong.