Two things have surprised me in this thread; 1) I didn't realize so many people wanted a Lion Pokemon only to be let down by Pyroar, and 2) I can't believe Specs was barely mentioned in this thread, only once as an OO. It's Pyroar's most common set, narrowly edging out Life Orb at the top of the ladder. Your "standard" Pyroar, if you wanna call it that, looks a little something like:
Pyroar @ Choice Specs/Life Orb
Ability: Unnerve
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
- Fire Blast
- Hyper Voice
- Hidden Power [Grass]
- Filler: (Flamethrower / Overheat / Will-o-Wisp / Hyper Beam)
Here we have it, your standard Pyroar if for no other reason than the fact that it really doesn't have many other viable options. Fire Blast is Pyroar's best Fire STAB attack, with a high base 110 power, and a reasonable base 85% accuracy. Hyper Voice completed the STAB combo with being Pyroar's strongest normal STAB with no drawbacks (and also the ability to penetrate Substitutes). From there, you run into issues with Pyroar's limited movepool. Naturally, when your movepool is bad, Hidden Power becomes necessary for coverage, and for Pyroar, this is no exception. Grass is the preferred Hidden Power type, as it prevents things such as Rhydon, Kabutops, and Carracosta from having free reign with Pyroar. From there... Pyroar basically just has to pick a filler attack. Some might consider Dark Pulse given it's pretty much the only semi-decent special attack it has, but sadly, Dark Pulse doesn't really give you much in the way of coverage. Instead, Pyroar can opt for Flamethrower for a weaker, but more accurate alternative to Fire Blast if you absolutley cannot afford to miss. On the flip side, Overheat has some early wall-breaking prowess with its high power, and synergizes well with Specs sets. Just be sure you're packing hazard control because switching in and out to deal with Overheat's special attack drop is just asking for Stealth Rock to shred you. On the more supportive side of things, Will-o-Wisp can be used to bait in and neuter some of Pyroar's best checks and counters, including Regirock who otherwise puts a stop to Pyroar by only being 3HKO'ed by Specs HP Grass. Will-o-Wisp can also be a surprise option on a Specs set against those who might not expect it, although getting locked into it is a bit of a bummer. Finally, the most unconventional option would be none other than Hyper Beam. Under normal circumstances Hyper Beam is pretty bad, because you can outdamage it with Hyper Voice over two turns, and the recharge turn makes Pyroar prone to revenge killing or being set up on. However, with Pyroar's limited movepool, it can be an absolute last resort in a do-or-die situation. I wouldn't recommend it as your first choice, ever, but it's a niche option.
Timid Nature with 252 Speed EVs is pretty obvious for maximizing Pyroar's speed, and that base 106 speed tier is pretty solid for outspeeding things such as Mismagius, Cryogonal, and Scyther. The rest obviously gets dumped into Special Attack to maximize power. Unfortunately for Pyroar, none of its abilities are terribly good, given that Rivalry has the potential to decrease damage, and Moxie is pointless on a special attacker, given Pyroar's attack is so low. Unnverse is sadly the best it gets, and even then it's rather situational. With respect to items, Choice Specs is the most used to maximize Pyroar's power. However, Life Orb is an alternative to allow Pyroar to switch attacks, but between the recoil, poor defensive typing (including the weakness to Stealth Rock), and mediocre bulk, you might find Pyroar dying a bit more quickly than you'd like.
On an unrelated note...
You're not telling me they didn't think Trapinch- the Dugtrio of Trick Room- wasn't worth covering!
Trapinch is actually quite terrible. Even in the Little Cup, the only place where it's actually viable, it's ranked D in viability; i.e., it's overall bad with a slight niche.
Speaking of which, Litleo is also ranked D in viability in the Little Cup. Being weak to fighting is a huge problem when the tier is basically ruled by Mienfoo (among other fighting types).