I have to say i've been waiting for someone to make a pony version of skeletor and when i saw this my heart leapt with joy.
Now onto the picture itself, the lighting is near perfect and i love the way you've done the reflection of skeletor on the water. The level of detail put into this is absolutely staggering and i love how much work you've put into the small things like the horn, hooves, ripples in the cloak etc.
My only problem is the staff looks half finished and the glow effect looks very weak compared to the glow effect you've added to the horn, maybe if you added the same effect to the staff then it would look much better.
Also i'm not sure if this was intentional but skeletor doesn't have a cutie mark, again this may have been intentional but to keep it within the MLP theme you could have added it in(something like a skull with crossed staffs or something).
Overall i really love this piece of work and it is definitely going in my favourites.
"Wait, before you start singing, He-man! Your singing always makes me smile in a weird way, like I did in that one He-man Christmas special. Anyway, let us not detract from the quality of the above image. I do not remember being transformed into a pony, but now that I see it before my eyeless slits it seems to be only natural! As I said when fighting She-ra; a villain must always be willing to change his tactics. And thus, the beautiful lighting around the horn and the staff, and my highly detailed skull in this picture, show that I am willing to look the part even when fighting you. Curse you, He-man! May my pony form destroy you!" "You speak the truth, Skeletor. May I now sing?" "You may sing."
"And so I cry sometimes When I'm lying in bed, Just to get it all out...what's in my head And I, I am feeling a little peculiar!
And so I wake in the morning And I step outside, And I take a deep breath and I get real high, And I scream from the top of my lungs: What's going on?
And I say: HEY! Yeah yeaaahyeahyeah, HEY yeah yeah; I said hey, what's going on?
"And he tries!" "Oh my god do I try! I try all the time, in this institution!" "And he prays!" "Oh my God, do I pray! I pray every single day- "MYAAAAH! "-FOR A REVOLUTION!!!