Now, it's not easy for these great emperors to unite. They were never united as one to begin with, even though some ambitious ancient emperors were filled with greed and did not wish to pay any price to snatch the secrets of the heavenly gate.
However, their thoughts do not represent all of the ancient emperors. Once any of the ancient emperors agreed to the trade of the heavenly gate, it actually meant that they might be excluded and become the new targets of public criticism, a situation those emperors did not wish to see.
After all, the heavenly gate currently boasts at least two ancient emperors of formidable strength. They stood on the same level as these emperors and were not to be easily oppressed.