I was going to use the season 2 pvp mount but I’m not going to get it. I was going to get it on Lunnaya, but they made unholy so effin boring to play in pve and pvp. I just can’t do it. Don’t have the motivation anymore.
So I’m officially hanging up the gloves on Lunnaya.
Rip Lunnaya
So now I’m leveling up a shadow priest.
I could do it in time if i leveled her up super fast and gear her really fast, but I’m a casual. Work and school reasons.
So any cool looking mounts to fit a shadow priest?
Dark Phoenix, Voidtalon of the Dark Star, Lucid Nightmare, Starcursed Voidstrider if you’re Alliance, just to name a few.
The Legion class mount is really cool, in my opinion. Especially the shadow version.
That one is pretty
The priest class mount from yonder order hall
Thank you for the suggestion 
Invincible
Corrupted Fire Hawk
Baron Rivendare’s Deathcharger
Hivemind
If you’re unlucky like me, none of these may be an option. I switch off between Tyrael’s Charger and Ironbound Proto-drake.
Bloodfang widow. With vrykul drinking horn and Tauren transform.
If you don’t have the Shadow Priest Class Mount:
Void Talon of the Dark Star
Corrupted Fire Hawk
Invincible
Dark Phoenix
Baron Rivendare’s Charger
Crimson Deathcharger
Starcursed Voidstrider (if Alliance).
A couple of the Ruin Striders from Argussian Reach Rep in a pinch.
The sandstone drake looks really good with the shadow priest aura.
I think there is a glyph that extends Shadowform to mounts and pets. Try some mounts and see what it looks like with Shadowform enabled!
The dark phoenix from the Firelands achievement. That one or the phoenix mount from the guild vendor.
the ones that transform you into something because your shadowform also transforms the mount
Not to necro a post, but I think Tyrael’s Charger looks really cool with a Shadow Priest.