This is Comet, Comet Trail. A grey pegasus-- Unicorn... Err, Alicorn? He's new in ponyville, and seems to hit thing off pretty well, well, as good as any socially awkward stallion can in a town that the spirit of chaos wanted to make into the chaos capital. He's rather cryptic and avoids talking about himself, but it's all okay since Twilight seems to trust him. Right? Why shouldn't you trust a cryptic and secretive Alicorn what just disappears in a blink of an eye and has a shadowy aura around him?
Anyway, this takes place after episode 13 season 5
On hiatus, until I know where I want to take things, or if I'll begin from scratch.
Thanks to:
*Zoetic-Zebra, for amazing cover-art.