They had already experienced a great defeat before, and with the situation from last time, those Ancient Powerful Beings were well aware that they were no longer at their best. Given the circumstances back then, if they were to face Zhou Tian, they knew all too well that they would stand no chance against him.
Moreover, considering the relationship between Zhou Tian and themselves, if they could not defeat Zhou Tian, those Ancient Powerful Beings wouldn't believe that, based on Zhou Tian's usual performance, he would let them off the hook at that time.
If they were defeated by Zhou Tian, it almost certainly spelled doom for them.
The situation at that time was simply unacceptable to those Ancient Powerful Beings.
