After all, people could escape outside of the domain through their own domain!
The Godfather could fight them and if he felt that he would lose, he could run away, and no one could even stop him.
The domain masters felt that they should be able to kill the man before he could create a domain.
Their preparation was already complete. They were confident with a basis, not a mere arrogance.
Indeed, in the real timeline, the Godfather died before he could create a domain.
However, now, because of Ainsley's interference, the Godfather was safe and sound. He even got an early enlightenment, which pushed him to create a domain earlier than in the real timeline!
The domain masters were all furious and deep inside, there was still a slight tremor in their heart.
They knew how powerful the Godfather was. His abilities were unique, but to be honest, compared to soul masters, his abilities were ordinary.