Depends on your team needs. here's a set for each and you see what fits in better.
Haxorus @ Life Orb
Trait: Mold Breaker
Jolly Nature (+Spd, -SAtk)
EVs: 252 Atk/ 252 Spd/ 4 SDef
- Dual Chop
- Earthquake
- Brick Break
- Swords Dance
i use this set myself. Jolly Nature helps outspeed most things outside of 100 base speed range. Dual Chop is used to break Substitutes and damage. For in game, you can always use Dragon Claw or Outrage instead. Earthquake is great coverage and Brick Break hits Ice Type threats. After even just one Swords Dance Haxorus's attack goes from 393 to a staggering 786. Life Orb then adds 30% damage to all attacks. can you say ouch?
Hydreigon @ Life Orb/Focus Sash
Trait: Levitate
Modest Nature (+SAtk, -Atk)
EVs: 252 SAtk/ 252 Spd/ 4 HP
- Draco Meteor/Dragon Pulse
- Fire Blast/Flame Thrower
- Focus Blast/Dark Pulse
- Protect
this set uses either Life Orb to hit ridiculously hard, or Focus Sash to make a better revenge killer.
Draco Meteor, Fire Blast, and Focus Blast and all powerful but have drawbacks. Dragon Pulse, Flamethrower, and Dark Pulse are a bit more reliable. if you're going to use thLife Orb I recommend just using the raw power, while using the second options with Sash. you could also use any combination you see fit, but I recommend Protect as a scouting option and for Outstalling a Toxic Stricken opponent.