It does look like a wrestling heel... But that's part of the point. It looks like a WRESTLER. That's a fighting style. Heck, it's shown grappling two different Pokémon in its concept images. Storm Throw, Circle Throw, Submission, Seismic Toss, Vital Throw... They're all Fighting moves, because it's a fighting style.

The Litten evolution's design would be more believable as a Fighting/Dark than a Fire/Dark.
I mean, Emboar looks like Fire/Dark from the design as well.

But it's not.

But, really, I just... I really hate that design. It goes from a sleek, standoffish kitty cat that doesn't express itself well to a big, hulking, bipedal thing that is barely a cat anymore, and doesn't even really seem evocative of a Fire type.