Note that Emperor Cole was correct in that Primal Earth is an existential threat to Praetoria. Primal Earth has the Hamidon contained and has plans in the works that we know are effective to defeat it - we defeat it pretty much every time it respawns. That leaves two possibilities. First, that Primal Hamidon is just as powerful as Praetorian Hamidon, and Primal Earth's heroes will eventually come and defeat Praetorian Hamidon because it's horribly dangerous even if it isn't actually unstoppable, which will remove Emperor Cole's whole justification for seizing absolute power. Second, that Praetorian Hamidon is significantly stronger than Primal Hamidon, in which case Primal Earth's heroes will eventually come and attack Praetorian Hamidon, fail, and irrevocably break the agreement Emperor Cole has in place that allows Praetoria to continue to exist. Either way, Emperor Cole loses, unless he can subdue Primal Earth before it happens.