"Retreat!" Even though he was extremely unwilling, the Void Zone Lord had no choice but to give the order to retreat. Even though he still had many half-step Domain Monarchs, he could already tell that these half-step Domain Monarchs would only be slaughtered by Rong Mo.
Even someone as strong as Sheng Tian and as cunning as the Saint Dao Heart couldn't win against Rong Mo. Who else could defeat him? At least a single half-step Domain Monarch couldn't do it. There were probably ten half-step Domain Monarchs! Only then could he surround and kill Rong Mo.
But was Rong Mo that easy to kill? No, his Four Symbols Divine Beasts could easily divide people into different groups. Therefore, all the half-step Domain Monarchs present could only be slaughtered.
If he didn't see through this, why didn't the half-step Domain Monarch of the Saint Clan kill him for revenge? Because they were afraid! They knew that they had no chance of winning.