There were always worlds upon worlds, that Azrael, Michael and Duma were different yet the same made no difference at all to Imagination. Once, long ago, Michael had been a comfort but that was before the Fall and before the Winchesters, back when Raphael still knew how to heal and Samandriel himself had been free to sink his toes in the grass and let his Grace brush who he pleased.
Before Duma was even done speaking Castiel's name, Samandriel'd brought his wings in tight, instinctively trying to protect himself from the sharp pain first from abandonment and then from betrayal. He let out a loud yelp of pain. Those weren't ready to be moved yet, much less as quickly as he had.