If it were in the past, the original rules in that Treasure Space required slaying specific living beings to obtain that special energy. In that case, apart from allowing those Giant Beasts to freely breed within the Treasure Space, Zhou Tian would find it very difficult to profit using the rules of that space.
However, since Zhou Tian already possesses the control over that space, the rules of that space have already changed due to Zhou Tian's modifications. And according to the current rules of that Treasure Space, as long as Zhou Tian ensures that the internal combat within that space can gain that special ability, there is no worry about the rule he set becoming useless over time.
However…
Although theoretically speaking, even if Zhou Tian does not let other living beings enter it, as long as there are living beings inside that space, even if those Deities have internal conflict, they can still obtain what they want in that Treasure Space through fighting.
