After everything goes down, after the Apocalypse-that-never-was and all the shit Heaven and Hell put them through, Aziraphale and Crowley decide to settle down, take life at their own pace
Of course, with nothing else to fill his time (since tempting is out of the picture what with Hell despising him and whatnot) Crowley decides to take up songwriting
And the name he chooses ? Why, Hozier, of course