Here is my opinion about the theorymons and the reason why i put them in the slate:
Fur Coat Aromatisse (Red Coat)
Fur Coat Aromatisse is a great mixed wall, that can check or wall all kinds of scary attackers such as Garchomp, Mega Pinsir, Roost-less Mega Charizard X, Azumarill, BU-less Talonflame, Dragonite, Greninja, Deoxys-S, Latios, Latias, Rotom-W, Mega Medicham, Mega Tyranitar, Mega Garchomp, and Mamoswine, just from S and A ranks. This is the kind of mixed bulk that OU has been lacking, and Aromatisse will make a great addition for balanced and stall teams, being able to deal with a ton of Pokemon and provide ample of team support with Wish and Aromatherapy. Why it won't be too strong defensively? Because many Pokemon can get past it or counter it, such as SD Aegislash, Mold Breaker Excadrill, Kyurem-B, SD Mega Scizor, Mega Gyarados, SD Bisharp, Mega Charizard Y, NP Thundurus, Sludge Wave Landorus, Calm Mind Unaware Clefable, SD Mega Mawile, Gengar, BU Talonflame, Mega Gardevoir, Suicune, and Diggersby, among many others. It's basically a really physically bulky Fairy-type that isn't afraid to switch into strong physical attackers like Clefable, and can actually wall special Pokemon unlike Quagsire, while obviously being also much physically bulkier than it and being able to wall Pokemon such as CB Azumarill, Mamoswine, and Mega Garchomp that Quagsire can't.
Extremspeed Braviary (Valmanway)
I love this one! With priority as strong as Talonflame's but with the ability to outrun opposing priority users, Braviary has finally a reason to be used. Defiant it lets punish Defog users pretty hard, sweep offensive teams in a moment's notice. For example, here is how much a +2 LO ES does to even bulky offensive Pokemon:
- +2 252+ Atk Life Orb Braviary Extreme Speed vs. 4 HP / 0 Def Garchomp: 374-442 (104.4 - 123.4%) -- guaranteed OHKO
Anything frailer is easily OHKOed, which is pretty much any faster Pokemon that isn't a Ghost, Steel, or Rock-type. What about those you say? Let's see:
- +2 252+ Atk Life Orb Braviary Extreme Speed vs. 4 HP / 0 Def Tyranitar: 165-195 (48.2 - 57%) -- 91.8% chance to 2HKO
- +2 252+ Atk Life Orb Braviary Extreme Speed vs. 0 HP / 0 Def Terrakion: 195-230 (60.3 - 71.2%) -- guaranteed 2HKO
- +2 252+ Atk Life Orb Braviary Extreme Speed vs. 4 HP / 0 Def Mega Aerodactyl: 205-242 (67.8 - 80.1%) -- 43.8% chance to OHKO after Stealth Rock
- +2 252+ Atk Life Orb Braviary Extreme Speed vs. 4 HP / 0 Def Excadrill: 270-320 (74.5 - 88.3%) -- guaranteed 2HKO after Stealth Rock
- +2 252+ Atk Life Orb Braviary Extreme Speed vs. 4 HP / 0 Def Kabutops: 172-203 (65.6 - 77.4%) -- guaranteed 2HKO after Stealth Rock
As you can see only Choice Scarf Tyranitar and Choice Scarf Terrakion can reliably revenge kill Braviary, as anything else is OHKOed with just a tiny bit of previous damage, which can be achieved with SR or Spikes. And thx to Defiant, Landorus-T fails miserably to check Braviary. What about slower Pokemon that offensive teams can use and can take a hit from +2 Braviary?
- +2 252+ Atk Life Orb Braviary Shadow Claw vs. 252 HP / 0 Def Aegislash-Shield: 294-348 (90.7 - 107.4%) -- 81.3% chance to OHKO after Stealth Rock
- +2 252+ Atk Life Orb Braviary Superpower vs. 132 HP / 0 Def Mega Mawile: 296-350 (108 - 127.7%) -- guaranteed OHKO
- +2 252+ Atk Life Orb Braviary Extreme Speed vs. 252 HP / 252+ Def Rotom-W: 247-292 (81.2 - 96%) -- 56.3% chance to OHKO after Stealth Rock
So, offensive teams have to use either Gengar or Choice Scarf Terrakion / Tyranitar if they want to be able to use Defog with Latios and Latias. Of course Braviary will get OHKOed if it switches into Draco Meteor, but even if it does, the hazards will have stayed up, and Braivary will have fulfilled its duty. As for defensive Defog users, while they certainly fare better against Braviary, they can still lose:
- +2 252+ Atk Life Orb Braviary Extreme Speed vs. 252 HP / 240+ Def Zapdos: 290-343 (75.5 - 89.3%) -- guaranteed OHKO after Stealth Rock
SR + 1 round of lefties will have taken place for Zapdos, as it will have switched in with SR up and used Defog as Braviary comes in, and Braviary has a very good chance to OHKO.
- +2 252+ Atk Life Orb Braviary Brave Bird vs. 252 HP / 252+ Def Mandibuzz: 374-442 (88.2 - 104.2%) -- guaranteed OHKO after Stealth Rock
Same with Zapdos, but instead Mandibuzz always dies to BB after SR and 1 round of lefties.
- +2 252+ Atk Life Orb Braviary Brave Bird vs. 252 HP / 232+ Def Skarmory: 153-182 (45.8 - 54.4%) -- 97.7% chance to 2HKO after Stealth Rock and Leftovers recovery
Here is the first Defog user able to counter Braviary even if it switches into Defog. Skarmory can gradually weaken Superpower with constant Roosting, so it is able to counter Braviary. Which means that defensive teams with Skarmory are fine against Braviary, but Zapdos and Mandibuzz need to tread lightly.
However, even if Braviary doesn't manage to get the Defiant boost, you still have a priority user with the same power of Talonflame, that has better bulk, is less weak to SR, is way stronger and with way better coverage which means it is way harder to wall, and which can also outpriority any Pokemon in OU, unlike Talonflame which loses to stuff such as Aqua Jet Kabutops in rain, Extremespeed Dragonite, and Thunder Wave Thundurus. Even without Defiant, Braviary still has many reasons to be used. And to top it all off, Braviary dgaf about King's Shield and Intimidate unlike most physical attackers, and has a very good competitive movepool consisting of Brave Bird, Shadow Claw, Superpower, Brick Break, U-turn, Substitute, Bulk Up, and Roost, allowing Braviary to run multiple sets such as LO all out attacker, bulky BU sweeper, and CB user. However, Braviary is very checkable, especially if you don't use Defog as it switches in, and even then it can be walled. Without the +2 boost, a ton of Pokemon can check and counter it, so it's very manageable.
tl;dr this theorymon is the second coming of jesus, Braviary will change everything in OU, vote for it and you will see it. (pardon the obvious exaggeration but honestly it's really good :D) And i included it because it checks a ton of offensive Pokemon while being very manageable for defensive and bulky Pokemon.
Regenerator Starmie (Tomahawk9)
Regenerator will make Starmie's bulky sets viable again, freeing up a moveslot to use Thunderbolt or Ice Beam. Scald / Psyshock / (Ice Beam / Thunder Wave) / Rapid Spin is a good moveset, and with max HP, Starmie can check Pokemon such as Keldeo, Mega Gyarados, Terrakion, and Garchomp. And while it's true that it can't switch into a lot of Pokemon, a fast Rapid Spin with respectable power and coverage could make Starmie very useful. Scald says fuck you to Aegislash and any Pursuit user, so that's great too. Overall though, i am not that impressed about this one, though Mienshao has already showed us how great Regenerator can be on an offensive Pokemon even if you are frail as fuck, and Starmie has more bulk, resistanes, and huge utility with Rapid Spin, so i think even offensive sets will be way better with Regenerator. It's an interesting theorymon in a vague way as the right elements are there, but i can't really imagine how they will combined together to make Starmie better in this metagame. I think it has potential though, which is why i included it.
Sticky Web Accelgor (Jaroda)
''Why will this be any different from Sticky Web Galvantula or the Prankster Sticky Web Volbeat theorymon that nobody voted for alexwolf?'' is what some people may think and the answer is simple: Final Gambit baby! With Accelgor's blazing Speed, Accelgor can suicide to prevent any Defog or Rapid Spin from getting rid of Sticky Web, while simultaneously allowing you to bring in the correct Pokemon and keep momentum. This is huge and can't be stressed enough. Accelgor is the Sticky Web user that can keep Sticky Web up for the longest time out of all the other users, and the most reliable at doing so. Add to the mix Spikes, Yawn, and Encore, which can cause a ton of switches and give enough time to Accelgor to set up both hazards, and you have a great suicide lead at the very least. So, Accelgor would be the most viable Sticky Web user imo, and it would be very interesting to see its impact on the metagame, which is why i included it, as it's a shame that the best existing Sticky Web user is Shuckle.
EDIT: Damn me and my silliness, again forgetting that one of the competitors is B-. Sorry guys, i will be more careful from now on. Even though Starmie can't be voted on later, you are still free to discuss its potential in OU.