Oh my gosh. You captured Vash perfectly. He's so adorable yet so cool at the same time~ I know this is probably an old sketch, but it would be cool if you drew him with his sunglasses glowing...much like here: www.pureanimegallery.com/d/171…
I understand though that it would be hard to pull off due to the large eyes of this style. Still, it's nice to imagine. x3
I think my 2 favorite faces would have to be his "Utter surprise" face and his top right face. x3
Or maybe since he's a plant he doesn't HAVE a cutie mark. His cutie mark could even be a gun? I dunno. xD Vash is such a complex man. Maybe his cutie mark could even be ruined from his countless scars? o3o
Some crossovers don't work, most are "alright", and a few are "omg PERFECT." This is perfect! the costume is great, but what really sells it are the faces. They look just like Vash in the anime, and it is practically a 1:1 translation of the face to a pony and it just. works. perfectly!
You did a very thorough job with the duster and hair... if only we had a pose with his signature revolver. Alas, he is just a nincompoop pony with a 60 billion bit bounty on his head... and terrible news for insurance companies.
Let's see... being called a "stampede" as a single pony is roughly equivalent to being called, as a human being: 1) a riot 2) a one-man army 3) a MAN STORM