There IS a canonical Cyberman story called The Tenth Planet. It was the Cybermen's debut story and William Hartnell's final story as the First Doctor. If you knew this already when you created this pic, then my hats off to you, Trotsworth.
And yes, there are ten ponies in this picture; you have to strain to see them, but there's Dash and Shy in the sky.
And Octavia looks SO CUTE in a Cyberpony outfit! Overall, awesome picture. ^_^
I'm sorry- I just can't see that any living creature converted by into a Cyberman, which involves switching body parts for Mechanical Appendages and removing Emotions through SURGICAL Means, could be so easily returned to normal, especially through taking their armor off.
A quote from Tetrap.com "The Machinery of Survival, Cyberfaction and Cybernisation" states: "To become a Cyberman means losing one's physical appearance, one's capacity to reproduce sexually, and one's emotional response to the outside world. It is the utmost removal of an individual identity - in short, a living, endless existence to which the respondent's own natural and moral reactions are denied.". Put Simply, Those who become Cybermen, are doomed to remain Cybermen and can only be Killed in order to free them. The only Exception to this rule is The Junior-CyberLeader "Kroton" and even He was essentially a Cyberman With Emotions. (Ignoring of course Craig from "Closing Time" because that Ending was just completely unrealistic despite how good the Episode was.)
In reality, if the masks were taken off those Ponies, it would look like a Pony version of this:
(This is not to say I hate your artwork *Trotsworth*, I like it a lot. In fact, I wonder if you could do any earlier versions of the Cybermen in Pony Form (Especially the "Tenth Planet' design which is my Favorite).
Which of course is completely against the Concept of the Cybermen,which is what would happen if a person had so many prostheses that they could no longer distinguish themselves between man and machine.
The idea of the Cybermen is to allay many people's fears about the direction of spare-part surgery. The original Cybermen were imagined as human, but with plastic and metal prostheses. The Cybermen of The Tenth Planet still have human hands, and their facial structures are visible beneath the masks they wear. However, over time, they evolved into metallic, more robot-like designs.
To make it just about controlling People's Minds completely detracts from the Cybermen concept.
It concentrates more about the modern cybermen tech fear of conformity and loss of individuality from mass produced consumerism. Rather than a more intense physical robotic fusion, it is more about the mechanisation of the soul.
But those Cybermen were the Cybus Cybermen from a Parallel Universe. And judging by their Cutiemarks, these CyberPonies appear to be of the Mondasian Cybermen Variant.
The TRUE Cybermen, wether you like it or not, was about the concept of humans replacing their body parts with Mechanics to Survive, to the point where even their Emotions are detrimental to their Existence and are therefore, Removed.