Here is a pretty powerful, fast offensive pair:
Lucario (M) @ Lucarionite
Trait: Justified
EVs: 252 Atk / 4 Def / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Swords Dance
- Crunch
- Bullet Punch
- Close Combat
Salamence (M) @ Life Orb
Trait: Moxie
EVs: 64 Atk / 192 SAtk / 252 Spd
Rash Nature (+SAtk, -SDef)
- Draco Meteor
- Outrage
- Earthquake
- Fire Blast
Mega-Lucario with Crunch hates bulky-ground types, especially Landorus-T. Physical Dragon-types that use Draco Meteor make excellent lures to bulky ground types because they have decently high special attack stats and Draco Meteor has solid power behind it for a luring move. Compare a 130 base power STAB Draco Meteor to an un-STAB'ed 60 base power Hidden Power. Draco Meteor's advantage is that, even if you make a mistake and ruin the surprise, you can still make a hefty dent, if not a OHKO, on something.
In this case, I chose Salamence. Salamence offers the heftiness Draco Meteor out of the mixed-physical Dragon bunch (ChainChomp, Dragonite, and Salamence). In addition, Salamence and Lucario have resistances on most of each other's weaknesses (Luke: Ice, Dragon, and Rock Salamence: Ground, Fighting, and Fire). Unlike Dragonite, I do not sacrifice much offensive presence since Salamence has decent speed at neutral base 100 and Salamence has Moxie to continue very strong attacking even after using Draco Meteor.
Lucario in turn can annihilate any Steel-types that Salamence may have missed / have to play around, take chunks out of most defensive pokes with an Adaptbility Close Combat, and it can take out Fairies with a boosted Bullet Punch. Lucario shouldn't come out though until Salamence has torn chunks out of the opponents team (unless it can get an easy Knock Off bost :] ). While the analysis says otherwise, MixedMence I believe still remains a powerful option for wall-breaking / chunk tearing because:
1, Fairy-typed Pokemon have not as a whole had a large presence on the metagame. The only one that causes trouble for Salamence's current moveset that is present on a large amount of teams is Azumarill. Togekiss you see once in a while, but not much.
2. Bulky Ground-types are popular pivots right now on teams because of Aegislash. Salamence is able to lure in these targets easily and take them out. Also gets the nod for taking out Rotom-W.
3. Unlike most lures, Salamence's luring move (Draco Meteor) actually causes pain on the opponent even when you mispredict. The same can not be said for Expert Belted Hidden Powers or un-STAB'ed coverage moves like Grass Knot or Superpower.