So at the end of Episode 12 of Volume V, we get several major reveals — I'm focusing on one.
Cinder's left arm since the beginning of Volume IV has been covered up. In fact, some argued that there was something wrong with it. That was of course, an understatement. Apparently, her left arm is now a Grimm arm — similar to that of the Nuckalavee from Volume IV. We're also told that Ruby took her left eye & for most of that volume, Cinder was unable to speak as she recovered.
After watching Episodes 11 & 12 of Volume V, I have to wonder — did Ruby actually do anything? Cinder gets blasted by the Silver Eyes in Episode 11 & while it does bring her to her knees, there is no damage done — not even to the Grimm portions of her. I have no doubt that the Silver Eyes bring Cinder pain, but there's a difference between pain & having to replace major portions of your body. All on the left, I might add.
When Cinder stole the Fall Maiden's power back in Volume III, the hand she used was her right — the uninjured one. So I don't believe that comes into play otherwise she would be forced into using her left hand. So, where did the damage come from? The big, bad dragon is merely frozen atop Beacon Tower — but Cinder loses an eye & her arm? This sounds a lot like Salem getting to Cinder while she was knocked out — or even frozen by the Silver Eyes — & having someone like Watts operate on her in an attempt to salvage their Fall Maiden. Then she wakes up & Ruby becomes their scapegoat.
Maybe it's just me, but I was always doubtful when Tyrian said:
"Well, she took your eye."
Even if Ruby had awoken before Cinder while they were both on top of Beacon Tower — I don't see Ruby being the type of person who would walk over to a helpless individual and carve them up. In my opinion, Salem is manipulating Cinder through anger, hatred & a need for revenge.