I do think the figure in the picture is Aulus, but I don't believe he is possessed by Elidibus. If only because what we currently know doesn't point to Varis being that shocked about Elidibus's appearance. I could also see the Empire trying to make Zenos's death out as a rumor. They've lost four of their Legatus's now within a five year time span, and three of them in at most a years worth of time. If nothing else that has to be a big moral hit and damage control is needed. As well one would think it would be a plot point if Zenos's body dissapeared, though its possible the graveyard thing was actually a cover for the Garleans to place a fake body in Zenos's place.
Though, my own totally 100% thinking is true (not really) theory of what a possibly alive Zenos is doing?
Lahabrea is possessing him. Totally whats happening.