The fact that the aquadites took the initiative to contact him spoke to their interest in the offer, especially since he had been the one to promise to consider their terms. It appeared that just a whiff of the realization that he was willing to sell the method to Transcendent impunity was enough to awaken the hunger for this power and method.
After all, any reasonable person would have assumed that the humans would never sell such a priceless treasure. They had no way of pressuring human civilization since they didn't have the coordinates of this civilization. And at the time, it certainly appeared that the Emperor of Water would rather die than share the secret to Transcendent impunity.
Now, just the fact that he was willing to consider giving them the method to Transcendent impunity made them realize that they had the opportunity of a lifetime at their disposal at the moment.
