Second of all, there are some minor issues with your sprites, and I had to edit them quite a bit. As a spriter myself, here is just my constructive criticism: It's pretty obvious that you didn't look at Cobalion's Sugimori art at all, and just relied on the details present in its original B/W backsprite, which is hard to see. Your backsprite had many anatomically incorrect details, that I corrected myself. Also you didn't exactly change the shading/outline style of the backsprite, looks to me like you just resized it. The 4th Gen backsprites are in a slightly different outline style than the 5th Gen backsprites. The front sprite had some "missed" pixels from cleaning up a resized sprite.
Do not take my advice offensively, it just for future reference. You still saved me some trouble, and your sprite was decent enough for me to work with. Here is my edits:
You will be added to the credits
For future reference, actually look at the Pokemon's Sugimori art. (also if anyone cares, I changed my Oshawott backsprite a bit to fix an issue with anatomy where I made it too fat)