Dhormium failed his first Knowledge (religion) check. I will give some general info though, since he might know that, & I think at least one of the players knows it. Coeus was a titan. Before the Olympian gods took over, Zeus' father and his kind, the Titans, ruled the earth. They roughly parallel the giants in Norse mythology. I don't know that there's a parallel in the Egyptian or non-human dieties. Coeus was one of these titans. Dhormium was under the impression that they had been permanently imprisoned, and were powerless to give spells to clerics.
The priest frowns slightly, but bows his head respectfully.
"Coeus knows we need help here against the power of the beastmen. And perhaps I can help you to fight them more effectively. We must talk further. But now we have other business. It is the day of the bat, and I have come to there halls practice the ritual. Your presence is augered, as we have two who will meet Coeus today. Come," he says to Ehldannis," you will share in honor." He stands back and gestures to the door with his hand. Outside the party can see more black-robed figures.
The rest of the party who can speak Greek can follow the gist of the conversation.