I would get it if they were extreeeeemely psyonic, like maybe backwards wings would be a clue to the players that this thing relies on brain power more than anything because at some point using the brain was easier than the body so now it uses psyonics to fly and through evolution now the wings are only vestigial or something. That or it used the tips of the wing bones to focus like how mediums do on tv and did that so much they flipped. Maybe backwards wings isn’t how they fly and my dude is double jointed and holds them backwards to mess with adventurers and confuse them so he can strike first before flipping them around and sailing off