In this way, if Zhou Tian doesn't stop his actions, that True God cannot lower his defense at that time.
Undoubtedly, from any perspective, Zhou Tian's attack posed a certain threat to that True God. If it weren't for Zhou Tian's current actions already posing a threat to him, that True God would not have wanted to do anything else at that time.
Since showing his strength to make Zhou Tian retreat by himself was no longer possible, to avoid Zhou Tian using those tactics to deplete his city's energy, that True God had to make a decision.
Defense obviously couldn't be abandoned at that time, but in such a situation, that True God also had to take some kind of response. Therefore, given his circumstances, after hesitating for a moment, that True God decided to launch an offensive.