Alrighty it's time to compare some Pokemon. This time it's Haxorus vs Tyrantrum
Let's look at their base stats:
Attack: A massive 147
Special Attack: 60
Special Defense: 70
Special Attack: 69
Special Defense: 59
Haxorus pretty much outclasses Tyrantrum in every stat, except defense.
This damage calc is one of the only good things about Tyrantrum:
>0+ Atk Choice Band Weavile Ice Punch vs. 252 HP / 252+ Def Tyrantrum: 200-236 (54.3 - 64.1%) -- guaranteed 2HKO
It can take Physical Hits extremely well. Haxorus would die immediately.
Haxorus can dish out some incredibly powerful hits, like to this steelix:
>+1 252+ Atk Haxorus Earthquake vs. 0 HP / 0 Def Steelix: 214-252 (73.5 - 86.5%) -- guaranteed 2HKO
And that's after a Dragon Dance.
Now let's look at their movepools:
Haxorus has a very mediocre movepool, but it has access to amazing moves such as Superpower or Outrage
Tyrantrum's movepool isn't any better, it's actually worse. But it gets great moves like the elemental fang moves(including poison fang) and Rock Slide. If it gets Outrage in ORAS, all other dragons better watch out.
Haxorus has the ever-so-loved Mold Breaker, which can be used to take out them pesky Rotom-Ws everywhere.
Tyrantrum also gets a good ability, Strong Jaw. It boosts it's Elemental Fang moves by 50%, which is really good. Strong Jaw also boosts these moves:
Alrighty I think we're done here. You can use both if you like, but is prefer to use this guy:
Here's a good set for Haxorus
Haxorus @ Lefties or Lum Berry(your choice)
Trait: Mold Breaker
EVs: 252 Atk, 252 Spe, 4 Hp
Hope I helped!