Flapping devilings error me on all but one of my legits, but only when I wear it. No amount of patching and fixing has worked. So my point is RoP may not be fixable. I'm new to ActOR, but the reference body sprite is usually a Lord Knight, and I'm just guessing here, but maybe in this particular case it doesn't compensate well for a champion's snap-asura combo.
I know a really good spriter who could take a look at the acts and sprite, if there was something wrong she could figure it out, but she's very busy atm. The animation seems to play a part of the problem, so we could remove that. Or we can modify the item so that champions can't equip them. Don't worry that's a last resort. But that's all we can offer you at this time.