Contrary Infernape: Holy crap, what a monster! We've got Contrary Serperior, something that we thought would be nearly unstoppable in a battle. Though the problem with it is its lack of coverage, leaving it prone to things like Heatran without Hidden Power Ground and Mega Scizor and Ferrothorn without Hidden Power Fire. But with Infernape, while it lacks the excellent Speed tier that Serperior has, it has power and plenty of coverage to more than make up for it. With Overheat, Infernape becomes a very lethal wallbreaker that's capable of breaking through defensive teams, granting it a free Nasty Plot boost after each hit, and the initial hit is pretty powerful as well. But Contrary doesn't just raise its offensive potential, but also improves its defenses thanks to Close Combat, which lets it threaten Heatran and could let it pull off a bulky wallbreaker kind of set. Add a burn immunity and Slack Off to the mix, and you have what can potentially be a monstrous force to be reckoned with. While it might not have the defenses or the Speed (to an extent) to get a boost, it can always forgo a bulky set and use a powerful Choice Scarf set to revenge kill and potentially start a sweep from there. I'm curious to see how this would perform in OU, and just can't resist voting for it.
Intimidate Mega Garchomp: Mega Garchomp is usually seen without using its ability, and seeing as it only activates when Tyranitar and Hippowdon are present, it shouldn't be surprising that Sand Force sees seldom use. With Intimidate, Mega Garchomp can pose as a threat to physical attackers, as it's already able to take a hit thanks to its almost unreal natural bulk, but Intimidate means even Azumarill of all things can't always OHKO:
-1 252+ Atk Choice Band Huge Power Azumarill Play Rough vs. 0 HP / 0 Def Mega Garchomp: 318-374 (89 - 104.7%) -- 31.3% chance to OHKO
So with this, it's perfectly clear that unless you use super effective attacks, even hard hitters like Mega Metagross and Excadrill fail to 2HKO without hazard support, thus making Mega Garchomp an amazing tank at times. Top this off with Mega Garhomp's already great offensive potential, it can act as a half wallbreaker, half physical sweeper stopper, so it has multiple uses on a team which will really make choosing between it and another Pokemon tough. I honestly really like this Theorymon, and wouldn't mind it at all if this won.
Tail Glow Raichu: This one took me by surprise, but while it does seem like a ludicrous buff, I'll have to admit that I like it. With just a single Tail Glow, Raichu is capable of 2HKOing Chansey of all things with Focus Blast, which should be a huge indicator of its sweeping prowess. Consider the fact that it gets moves like Surf, Grass Knot, and Focus Blast to help in the coverage department, and Raichu can very quickly turn into a problem for defensive teams, and even offensive teams if given the right support. However, Raichu's defenses will rarely ever hold against attackers, and 110 Speed is only the bare minimum for a sweeper these days, so its role would be best served as a wallbreaker. However, that role is challenged by Manaphy, who has much more bulk and Hydration + Rain Dance + Rest to keep itself healthy, so Raichu might have difficulty functioning in OU. However, Raichu can really clean up when it actually does get said support, as adding +3 to even base 90 Special Attack can lead to some pretty powerful results. It's not an amazing buff, but I do find this interesting nonetheless.
Steel / Dragon type Mega Aggron: This one's a bit weird, but still has its uses. With the new secondary Dragon typing, Mega Aggron sheds its Fire weakness and gains Water and Electric resistances, which is good for facing Azumarill, Mega Charizard X, Thundurus, and Mega Manectric. Losing Dragon, Ice, and Fairy resistances might be a bit unfortunate, but the extra resistances let Mega Aggron approach bigger names more easily, and Mega Aggron can take attacks pretty well anyways. It also powers up Dragon Tail, which can add onto hazard stacking damage quite nicely, as well as Dragon Claw to dish out the pain on some Steel resistors, such as Keldeo, Rotom-W, Mega Charizard X, Talonflame, and Mega Gyarados, so Mega Aggron benefits from the type change defensively and offensively. Not much to say about this one, but I feel that this is all that I need to say. I like it, and would be fine if this won.