
See that line in that red box? that appears in both [Blade_Skin] and [Blade_Mutilation]. I think that's what causes the problem.
Try to detach the whole arm from both [Blade_Skin] and [Blade_Mutilation] and then place the arm in the right position where you don't see that line. Then try to test it again in game.
Let me if that fixes your problem.
