Board Thread:Speculation House/@comment-69.66.169.227-20130802171349/@comment-2080866-20140606111519

To be fair, concerning the Nevermore, Ruby wasn't just running up the mountain under her own power or her own momentum from CR. Weis's circles were also giving a boost. (Side note to the person mentioning those and dust: those circles are Weis's special ability, and unrelated directly with dust (as was mentioned in one of the episodes, where special abilities and aura are mentioned).)

It can clearly be seen from the White Trailer that they can be used to enhance movement and this can also be seen when Ruby is launched (as there's no way she'd have made that jump without it, thus why it was part of the plan). It can also be seen in several places that it can be used even in mid-air with no actual physical ground, showing that it can grant force all on its own to someone benefiting from it. So it's very likely that those were also giving Ruby an additional vertical push.

So, all that being said, regardless of what the Nevermore is made of, inside or out, with enough force behind the slice, it will be cut.