As said many times before, the demon's ability to perceive demonic energy is very acute.
It is also said that they are very strict about bloodline superiority.
So, now this is where a question comes in.
What would happen if a group of demons felt the most powerful form of demonic energy they had ever felt, along with the strongest and purest bloodline ever?
The answer was simple: total submission.
That's what they would do.
They won't even raise their heads until the one with those two superior qualities orders them to.
It won't change their mindset, nor will it make enemies turn into friends, but as the rules of the demon capital states; no demon would raise their head.
Whatever frustration, anger, or any other rebelling thoughts they have will stay in their heads until they are in front of the said being, at least.
That is what happened the moment Alex released his incubus bloodline along with his demonic energy.