I really like the pose ^_^
The head and neck follow through with the position of the body nicely, it doesn't look like he's breaking his spine to be able to do that which is the usual mistake for this kind of pose so kudos on getting the anatomy perfect :D
Also the angle which he's flying is really nice and realistic.

The only critique I can really give you on this is that perhaps the blue night sky is a little out of place?
I would suggest either making it a little darker and perhaps adding some gray to the bottom to show the smoke, or if it's a BIG fire then maybe a burned orange might help show off the glow of the fire a little?

But all in all this looks lovely! ^^ nicely done!!!

I thank you for the critique :)

About the artwork: Done in PS, digital on my own and I tried to draw him in MLP style and I’m happy with the pose as well ^^

Background/rest: I see what you mean. Yeah the sky should maybe be a bit darker to show the night sky (maybe even stars also), I should add smoke, trees that are burning in the distance and smoke, not to speak about the glow from the fire.

I shall try and get back to this one and improve it one day.

I'll be honest I'm not overly familiar with MLP ^^;
I know what it is and what it looks like (can probably tell you most of the ponies names from seeing fan arts everywhere of em XD)
But I don't watch it myself so I'm not sure what the other creatures in that show look like ^^;
But that's not to say that this doesnt look good, this looks really nice ^_^
Like I said above, the pose and anatomy and everything looks really nice... I really like that you thought about his spine and how it moves when you drew this.
The fire also looks really cool ^_^ nice affect.
The background is the only thing I can critique, but to be honest I personally find backgrounds really hard XD so I understand it's not so easy to get the background perfect.
I think this is a nice looking image though ^^