Are you kidding me? Zuruzukin is bulky as fuck, CB Staraptor's Brave Bird does 79.6% - 94% to Max/Max Zuruzukin after an intimidate.
If Staraptor, with a choice band and max attack, can't OHKO him with a 120 BP STAB Super Effective attack, well, you get the idea.
On that note, lead machamp does 46.7% - 55.7% with Dynamicpunch, but that's kinda moot.
Not to mention he has great attacks like Fake Out, Counter, Dragon Tail, Bulk Up and the new and improved Drain Punch to aid him defensively.
Looking at him offensively, he's a strange one.
Fighting/Dark is an amazing offensive combination, hitting Ghost, Dark, Steel, Normal, Ice, Rock and Psychic for Super Effective.
Fighting is one of the best offensive types in the game, resisted only by Bug, Flying, Ghost, Poison and Psychic.
Ghost and Psychic are handled with ease by Zuruzukin's secondary STAB, and Bug and Flying are taken care of by Rock. Poison isn't a huge problem with the most popular poison type being Gengar, who's trounced by Dark.
And as far as Dark, Fighting and Rock goes, Zuruzukin is about as good as it gets, with STAB Crunch and STAB Hi Jump Kick, which was upgraded to 130 BP this Generation, and access to Stone Edge, Rock Slide AND Head Smash. Take your pick.
So since there's really no reason NOT to use those moves, Zuruzukin will pretty much always have room for one more move, whether you want a boosting move like Dragon Dance or Bulk Up, or maybe you want Fake Out to get that extra little jump on the opponent.
Unfortunately for Zuruzukin, his speed lies 3 points below Tyranitar, meaning that even after a DD, he's pretty slow. But on the plus side, he has no 4x weaknesses and only 2 weaknesses overall, as opposed to Tyranitar's Water, Fighting, Steel, Bug, Ground and Grass.
Likewise, his base attack lies at a modest 90, meaning aside from his awesome STAB attacks, he lacks the ability to hit hard from the start. Fortunately though, he can scare alot of things out since he can easily take a hit, and boost whatever he wants while the opponent switches out, or just kill with Pursuit. Whatever floats your boat.