I think the flying hands are really cool. In your concept sheet and silhouette 2, they were hovering over the character which i think is perfect to evoke nightmare, like an oppressing weight over the victim. It fits the superpower, those Morphean boulder paralyze you/lock you down.
Though i think you're going to have to make a choice between the wings or the hands, having both will probably lessen the impact of both, they'll compete for attention, which would be a disservice to your concept
Hope it helps
Good luck !