What in the Hades
A fancy way to say what the hell, etc. May be considered an euphemism under certain circumstances. Better used for formal discussions about a subject, whether specific or not.
Me, about atheism: As for Hunnic atheism... well, it was more of a "focus" on the here and now rather than a belief. They never thought on tomorrow, or what in the Hades could be behind those mountains. There was no "beyond" for them.