Angels as a race.

The race of atheists already exists — the Academy mages. There is no point in making another one

That's not an argument. According to your logic, there would have been no point in creating all other races after... for example, the elves, since elves have a deity, and if someone has a deity, then why create more races with deities?
"Atheist" angels would help remove the religious-mythological inaccuracy — the kinship between dragons and angels. And overall, I think it's important now to think through the ideology of this race, and it should be such that these creatures require no patron other than, say, an abstract One Creator. If we can't come up with anything coherent, then we should settle on Elrath as the patron of the Celestial Stronghold.