Well this certainly caught me by surprise. It's a delightful surprise, but still a shocker to see three of the four Theorymons from the last slate back in the current slate. But hey, I'm not complaining.
Dragon Dance Krookodile: Dragon Dance Krookodile looked to be a nasty foe to face from the last slate, and that opinion hasn't changed for this slate either. While its abilities Intimidate and Moxie are taking two pages out of Gyarados's book, that's where the similarities end. STAB Earthquake and Knock Off are pretty potent on their own, so sweeping can be pretty easy to pull off without being heavily reliant on a coverage move. 92 Speed is also respectable for a Dragon Dancer, as being able to outrun Landorus-T after a single boost is a luxury on its own, and 117 Attack combined with decent 95 / 80 / 70 defenses makes setting up and sweeping none too challenging. But as any Gyarados user can tell you, Intimidate and Moxie each have their unique uses, with Intimidate weakening physical attackers and potentially providing more setup opportunities, and Moxie creating a snowball effect after it gets a KO, so it shouldn't be a surprise to see Krookodile abusing these tools efficiently. Yeah, seeing this one win wouldn't be surprising.
Poison Heal Gastrodon: Despite the majority of people disliking this, I kind of like Poison Heal Gastrodon. I can see where the comparisons to Gliscor come from though; aside from its Water typing and more specially inclined stats, Gastrodon does seem like another Gliscor. However, while I wouldn't be the least bit surprised to see a fully defensive set, I'm more interested in seeing how a Curse set would perform. With a passable base 83 Attack, powerful STABs like Waterfall and Earthquake, and a respectable defensive presence by virtue of its defensive typing and stats, a Curse set already sounds possible. But one of the big reasons why Curse sets rarely work is because of the vulnerability to status like Toxic and burns, with the former greatly limiting how long they can stay, and the latter crippling their power. However, Poison Heal provides Gastrodon with status immunity, which is a key trait for setup sweepers, and the healing factor is merely a bonus. Swords Dance Gliscor kind of does this already, but Curse takes a more tankish approach, so I would kind of like to see where this would go if it wins. Just makes me wish we could vote for two things, y'know?
Drought Typhlosion: Basically a better Mega Charizard Y in almost every way, half because it isn't a Mega Evolution, and half because it has a lot of potential on its own. Not costing the team its Mega Evolution and the ability to hold items are traits that some people take for granted, and this is really where Mega Charizad Y is outclassed. While Mega Charizard Y has solidified itself as a powerful wallbreaker, Typhlosion can perform the same feats just as well, if not even more well. Lacking a 4x Stealth Rock weakness is a big plus, so even though using Eruption will be difficult, it still has Overheat and Fire Blast to provide the raw offensive power. Typhlosion also has Solar Beam and Focus Blast just like Mega Charizard Y, so if you like the latter's coverage, you'll like the former's. This, combined with Life Orb Typhlosion's attacks dealing almost the exact same amount of damage as Mega Charizard Y's attacks, means that Typhlosion can match its power if being used as a wallbreaker. But the real fun comes from the ability to hold a Choice Scarf. With a Choice Scarf, Typhlosion acts as an efficient and powerful revenge killer, and while it won't hit as hard, the trade-off is plenty fair, since it can outrun a lot of Choice Scarfers and +1 sweepers, and its STAB sun boosted Overheats are still pretty lethal against offensive Pokemon. I've gone on and on about this one, so I'll cut myself off there, lol. Simply put, my favorite Theorymon on the slate, and will definitely get my vote.
Focus Blast Pidgeot: Oh hey, it's Tornadus-T 0.8 *yawn*... Just kidding! :p While Flying/Fighting coverage is already a thing that Tornadus-T is rocking, it's typically an inconsistent method of dealing damage by virtue of the very shaky 70 accuracy on Hurricane (unless you have a rain team, which means you can't use anything other than a rain team). With No Guard, Mega Pidgeot can land its Hurricanes and Focus Blasts with no worries of missing, making Mega Pidgeot more consistent. Mega Pidgeot may not have Regenerator to stay healthy after switching, the ability to hold an item, or physical moves like Superpower and Knock Off to mess with special walls, but Mega Pidgeot does have one of the biggest draws that a sweeper can have: consistency. While the potential power that Mega Pidgeot has isn't as great as Tornadus-T's, you never have to worry about Hurricane or Focus Blast missing, so you'll always be able to OHKO that Keldeo every time, unlike Tornadus-T when that unfortunate 30% chance to miss kicks in at the wort possible moment. A simple buff, but one that I like. Just like everything else here, I wouldn't be surprised to see this one win.