Well to be entirely honest; he seems kind of basic. Like a standard background pegasus. Not that that is bad, but that is how he looks. Adding some extra color might help him stand out some. Look hard at the designs of the mane 6 and ask yourself "What is the first thing I notice about this character?" Try to see different things in each of them that stand out to you and set them apart.
Rainbow has her mane for sure but think about how Twilight's hairstyle is unique or how it has that single streak of extra color to it. Tiny details like that that folks don't even notice actually help them to be noticed the most.
Of course these are only suggestions on how to change him. I can respect if you don't want to change his design.
For me, the horns and wings do it in; I'm not very liking of OCs with those sort of things. Very little have been okay with me, such as Gem, who belongs to Gem is a good, but ponies with dragon/demon/bat wings and stuff just... seem too strange XD
I pretty much agree with you. xD I feel like if you want to make an FiM pony, you should keep it in the FiM style. But this pony's reference almost makes it look like a G3 pony. :0 Plus the horns and wings are just cool, so I didn't mind drawing it. :3