Zhao Hai did not do this for no reason. He found the Goblin slaves to let the people on the ark know how the God race treated the people they had conquered. Zhao Hai wanted to find the dried corpses of the people of the church of Light to show the people on the ark continent how the God race treated the people on the ark continent.
Zhao Hai had done this because he knew the importance of publicity. If he wanted to become the God of the people of the ark continent, he had to do a good job of publicity. He had to maintain a sense of mystery while promoting. This was necessary.
Not only did he want to promote himself, but he also wanted the people of the ark continent to understand that the God race was evil and brutal. Only then would the people of the ark continent be grateful to him. Slowly, this gratitude would turn into respect, and finally worship. Then, Zhao Hai would become a God in their hearts.