No question about it -- BLACK DRAGON NINJA. Very cool figure.
I probably would've said RED NINJA VIPER if they hadn't STUNK UP THE FIGURES WITH BLACK PAINT WASH!

And while I do have something that'd clean them fairly well, it'd also take the Cobra logo with it. So much for that idea.
The Vypras always bugged me just a little because (a) they looked too much like Jinx, (b) I came up with that code-name for Hasbro and while on the one hand I'm pleased to see it still in use, it was originally intended for a vehicle driver that was categorically not a pair of ninja twins, and (c), they stunk those figures up, too, and for whatever reason, the legs on mine are a little glitchy. On the plus side, I did like the ornate ornamentation on their uniforms.
Storm Shadow -- as pleased as I was to see the 1988 version return, I didn't like the uniform color, and the weathering or whatever it was that they smeared on him made him look like he'd shared a winter cave with an incontinent bear.
Ultimately, this could have been a much cooler set if they'd left well enough alone in some respects.