Haxorus

With a good moveset and an Attack stat rivaling that of Rayquaza, Haxorus is a great choice for a Dragon attacker. Its performance is along the lines of many other top-tier non Shadow Dragons such as Palkia and Salamence. Although Haxorus falls behind in comparison to the heavy hitting Shadow Dragon-types, it's nonetheless a great budget option for players who participated in its Community Day.

Best PvE Offensive Moveset

• Dragon Tail is basically the only Quick Move worthwhile on offense, and it should pair with Breaking Swipe*.
• Dragon Claw is slightly worse than Breaking Swipe, but a viable option nonetheless.
• Counter is a good move, but it lacks STAB and synergy on Haxorus
• Surf, Night Slash, and Earthquake have no real utility on Haxorus.

Best PvE Defensive Moveset

• Dragon Tail is fantastic on Defense, but it's also very predictable and easy to deal with given the right counters.
• Counter is a bit weaker, but is just as viable as Dragon Tail due to hitting Steel Types harder.
• Breaking Swipe is virtually undodgeable, though it is rather weak.
• Dragon Claw is a 3-bar move that hits hard and is narrowly resisted. It's a wonderful move on defense!
• Night Slash is similar to Dragon Claw, and adds a different resistance profile. Though both are walled by Fairy Types!
• Surf is a reasonable move that pairs well with Haxorus' Fast Moves to make Haxorus hard to wall. Being 2-bar does slow it down a bit, though.
• Earthquake is powerful, but Haxorus is too frail to be able to use it reliably on defense. Though it does offer counter-coverage against Steel Types.

Counter is one of the best fast moves in the game, provides wide coverage, but lacks STAB. Dragon Tail deals high STAB damage and offers Dragon-type coverage, but sports only average energy gains. 

Breaking Swipe is an incredible Charged Attack - it Dragon Claw's STAB, decent damage and low cost, but also comes with a guaranteed Attack debuff. By extension, Dragon Claw is strictly inferior to Breaking Swipe. Night Slash falls behind in raw damage output, and isn't particularly strong, but provides Dark-type coverage and a small chance to proc a major ATK boost. Surf is a respectably efficient charge move that can be used frequently, though it doesn't always synergize well with Haxorus. Earthquake costs the most amount of energy by a large margin, and isn't recommended for this reason, though its valuable coverage and high damage threat are still appealing.