So I've composed of some pokemon viable in OU (according to the OU viability thread) and made a quick description on their partnership with Lucario.
NOTE: Building a Whole team around a 'mon is unadviced, however building a team around a core is a great idea. Lucario is a sweeper and can wall break as well.
P.S. I dont have the time to finish today, but each day ill keep updating it. Hopefully this helps so far.
The lead to any Hyper Offense teams. This baby acts as a suicide lead, dishing out stealth rocks and spikes as if this sucker was going to kill himself. You can run many variants of him, but the best ones are the ones that utilize T-Wave (slow down opposition, mental herb (faster taunters), skill swap (because screw magic bounce), and red card (to switch in on set-up sweepers)
If used on Hyper offense, its presence will be felt through spikes and stealth rocks.
Lucario less than spectacular weakness to fire can be countered by rain. This allows him to survive Hidden Power Fire from Choice Spec Latios:
252 SpA Choice Specs Latios Hidden Power Fire vs. 4 HP / 0 SpD Lucario in rain: 152-180 (53.9 - 63.82%) -- guaranteed 2HKO
This allows you to get a crunch off and K.O it with extreme speed.
It should be noted, there are quite a few variants of politoed. You just need to build one suiting your play style. A Choice Spec Hydro Pump hits like a train and very few pokemon can switch into it.
If you enjoy Rain teams, and have a weakness to fire on your team. Its still the best weather, and can the 'mon can check Lucarios weaknesses.
Take a moment to admire how badass this pokemon looks. Alright. Moving on. Terrakion and Lucario have been compared quite a bit, but the truth is they are two different pokemon. Wallbreaking is what Terrakion does best. If you plan on using his on hyper offense, you can Focus Sash this fiend and put stealth rocks on it. Now this may seem like a job for Deo-D (and I do believe this is done better by him) but the lack of offense from Deo is noticeable and Terrak hits like a train. For example, after a stealth rock lead, he is capable of hitting Politoed, OHKO tyraniter, ninetales, abomasnow, even cripping ghost pokes. This allows Lucario to come in and finish of the job.
You can run a few variants of him, if your in need of a wall breaker, Terrak does it best. Careful about getting Wall'd by Gliscor and Jellicents.
Great technician. However, Breloom is a sweeper. What makes this pokemon special is you dont have to run Technician ability. With toxic heal, you can switch Breloom on status inducers and go buck wild on their annoyers. Not to mention it has a Substitute variant available too. To add to its offense, it learns STAB technician mach punch, which is a great priotiy move to add to Lucario's ES. However, the pokemon has its flaws. Latios' and Latias'
are running wild, both these pokemon are a great check to Breloom.
on rain teams or hyper offense, but your team MUST have a counter Latios or Latias, otherwise after ripping apart Breloom, they can hurt Lucario pretty badly.
Meet the strongest ES user in OU. One could argue that Dnite is on the borderline between OU and Ubers. There are many variants of him as it can be rank as a tank, as offense, or even sub-roost. Dnite's offense just adds to Lucario and is well utilized on an offense team. Instead of turning him into a Physical Attacker, try special on rain with politoed, as he can main Thunder and Hurricane (STAB too!). However, the flaws are that its hurt BAD by multiscale, and gets crushed by Weavile's and Mamoswine's Ice Shards. It helps Lucario as it resists both fighting and fire, allowing Dnite to successfully switch in and show of his outrageous
if you decide to utilise a core with Lucario and Dnite. They resist each other weaknesses, and allows them to set-up.
No matter who faces this guy it deals damage. A great counter to dragons, and one of the few pokemon that can laugh at an Outrage from Kyruem-Black. A core of Ferrothorn, Politoed, and Lucario would mitigate away the fire weaknesses, and ensure further longetivity. Deo-D could be added, and with protect on ferrothorn, it allows you to scout the other team before sending in your Jackal sweep/set-up. The problem with this core would be that a choice band terrakion
would easily tear it apart with close combats, and if your lucario doesnt pack a bullet punch, then you may have to kiss the game good-bye.
on rain teams, but try applying Twave if your team lacks it as you dont want pokemon setting up on ferrothorn.