Ah, Combuskin! I don't have a lot of favorite middle-stage evolution, unfortunately, but from what I do, this has got to be one of them. I'm generally a pretty big fan of Hoenn and its Pokémon, so my bias-ness sort of does come into play here, but still, I like it. In-design, it's got the look of a fighter and rooster mixed in, which I believe they were aiming for, and seemingly, were quite successful at. Alongside, it's also got a decent move-pool, and could lead your in-game team for a decent amount of time.
What I'm most of this Pokémon is that it's the pre-evolution of Blaziken, which is one of my most favorite final-stage starters of all time.