Merry Christmas – and a story

You know, Santa didn't wear red armor until the Adeptus Cola Adversitarius began a rhetorical campaign to make his branding more uniform. Before that, he was just the messenger of Adeptus Terra that brought the Ultramarine's their presents on the Emperor's birthday. -HERESY!  Also, Santa is a Blood Angel. He delivers the Emperor's blessing once per year to all of the Empire. How he does it