Thread:Hatebunny/@comment-27654719-20161011093738/@comment-3361105-20161011204729

Only as of the New 52 is this the case.

Grant Morrison's Multiversity introduced that concept, but nothing in the New 52 explores the concept fully (Multiversity included). But yes, presumably, the Darkseid who was killed in Darkseid War was just another Avatar, if the Multiversity interpretation still makes sense post-rebirth.