Here are the battle videos for my matches, in case you want to see any of them:
vs Murkrow: UPGB-WWWW-WW4T-KMJF
vs Stryke: DLQG-WWWW-WW4T-KMKK
vs Equinoxe: 78FW-WWWW-WW4T-KML8
vs MD: KZ8G-WWWW-WW4T-KMM4
vs JackPK: 396W-WWWW-ww4T-KMZW
I didn't record vs Espeon because I'm dumb and thought I was out of space. My bad!
Anyway, I was pretty excited at the start of the tournament and immediately started planning a team based around mega sceptile, with a discharge rotom as a partner. Sceptile is one of my favorite pokémon, so I was STOKED about getting to use it About then, of course, is when I remembered that I wouldn't be able to use it against any X/Y games. Initially I was disappointed, but then I seized on the thought of unburden sceptile with natural gift, lansat berry, and acrobatics. First turn you get a 100bp flying attack, +2 speed, and +2 crit rate!
...except, of course, that I neglected to check that natural gift worked the way I remembered, i.e. the way I made it work in ASB so it would only suck
some of the time instead of
all the time. Since sceptile isn't a very strong physical attacker and doesn't get STAB on acrobatics, I didn't think just the +2 speed from unburden was worth it; I needed a stronger physical attacker to take over sceptile's spot. So I ended up last-minute redoing the entire team and not getting to use sceptile after all. =/ It was super cool to see Equinoxe using an acrobatics sceptile in the tournament!
I pretty much built my team around the two primary special attackers, mega venusaur and abomasnow. The rest of the team I set up to support those two. I knew I wanted a physical attacker to take on pokémon with high special defense, and one with fighting attacks in particular that could take out ferrothorn, since my offense was otherwise very poison-heavy. The other were chosen primarily for their typings: I was worried about poison, and sludge bomb most of all, and secondarily flying attacks, since so few pokémon in the format resist them, and I expected them to be the most common attacking types that I'd face. Ferrothorn handles both easily, and trevenant is a poison-neutral pokémon that nicely covers its fighting weakness and deals well with physical attackers in general. Shifty finally added some coverage against psychic-types, which venusaur dislikes, fake out, and speed control in the form of tailwind. There were also some brief considerations of beat up + Virizion shenanigans before I decided to use chesnaught as my physical attacker.
In the end, this was the team I settled on:
Abomasnow @ Choice Scarf
Snow Warning
Timid
12 HP, 252 SpA, 244 Spd
Blizzard
Ice Shard
Icy Wind
Grasswhistle
Abomasnow was the first pokémon on the team and the only one that didn't change substantially over the course of development. The team is designed to wear down the opponent as much as possible, then send abomasnow in to mop up whatever's left. The speed is set to let it outpace any other non-scarfed pokémon in the format outside of mega sceptile, and other than that all it wants to do is hit hard with blizzard. The other attacks don't really matter and are reserved to be useful in potential hail-mary situations, most notably grasswhistle, which could potentially stop an opponent in its tracks. If you're at a point in the game where you need abomasnow to be doing anything other than dumping snow on anything that moves, though, you're probably beyond help.
Special thanks to Kratos Aurion for getting me the choice scarf after I realized far, far too late in the game that I had neither the item nor the BP to get the critical component of this set.
Venusaur @ Venusaurite
Chlorophyll/Thick Fat
Modest
60 HP, 4 Def, 252 Sp Atk, 12 SDef, 180 Spd
Sludge Bomb
Synthesis
Safeguard
Protect
Once I decided not to use mega sceptile, venusaur was the clear choice for my mega. Thick fat is incredibly valuable in this format, since there are so few pokémon even neutral to fire or ice attacks. Because mega venusaur needs that ability to be really useful as a switch-in, I tried to lead with it as much as possible so I could go mega immediately and be ready to tank a hit if necessary.
Ideally venusaur would have hidden power fire over one of its defensive moves, but I made the mistake of leaving this guy to breed last, at which point I looked at various hidden power breeding guides and essentially went "screw this." The only pokémon that HP fire is better for than sludge bomb is ferrothorn (or bulletproof chesnaught), which I was definitely worried about, but I was really just too tired to care.
The set is pretty easy to use; sludge bomb destroys a very large number of pokémon in the format, and the other moves are simply for getting out of sticky situations. I originally used synthesis + light screen here, but swapped light screen out for safeguard because I was worried about status (and in particular teeter dance). I found myself wanting light screen again, though, particularly when staring down abomasnow, and only found synthesis useful in situations where I was already ahead.
I forget what the speed EV's let venusaur outrun, but it ended up outpacing all the other (mega) venusaur I saw, which was nice. Chlorophyll is pretty useless, only turning on if an opponent set up sun, but since overgrow is useless literally 100% of the time on this set, chlorophyll's what I went with.
Shiftry @ Focus Sash
Early Bird
Jolly
36 HP, 252 Atk, 28 Def, 28 SDef, 164 Spd
Fake Out
Snarl
Tailwind
X-Scissor
Shiftry was an unexpectedly valuable member of this team. The primary reason I went with shiftry over ludicolo for fake out was snarl, which I thought would help with a couple of the things I was particularly worried about: abomasnow's blizzard and strong special poison attacks in general. It's kind of a notoriously underperforming move, though, and moving to a much frailer pokémon than ludicolo seemed like a dicey choice to make on the basis of that one attack.
In the end, though, snarl was a huge help in many fights, and I often found myself choosing it over fake out even on the first turn Shiftry was on the field. Tailwind is another great move for a relatively slow, bulky team like this. I only used it once, but it was pretty nice when I did.
The maximum attack allows shiftry to OHKO exeggutor, which it did get to do at one point, and therefore help out a bit with venusaur's psychic weakness. I was usually more interested in using Shiftry's support options than attacking, though.
The focus sash turned out to be completely useless, since Shiftry always ended up taking chip damage and often ended up living through two or three attacks, despite low defense investment. The info on its stats is taken directly from the text file I made up when I was planning the team, and I think the shiftry I actually used had chlorophyll; early bird is the better ability for this team, but since I doubted I'd be seeing much sleep (since shiftry is immune to powders, grasswhistle is pretty much the only thing that can put it to sleep, and that's a rare and low accuracy move) and was super tired of hatching eggs I let it go with the somewhat less useful ability, and it never mattered.
Trevenant @ Sitrus Berry
Harvest
Careful
172HP, 4 Def, 252 Atk, 80 Sdef
Phantom Force
Poison Jab
Will-o-Wisp
Protect
Originally I had harvest exeggutor in this spot, inspired by the exeggutor Wolfe Glicke used at Worlds. Trevenant is a little less powerful and a little less bulky than exeggutor, but it's not weak to poison, one of the attacking types I was most worried about in this tournament.
Trevenant is intended primarily as a staller: it hits opponents with will-o-wisp, then hangs around forever relying on harvest to give it unlimited sitrus berries and protect to let it avoid damage and get extra chances at a berry. Phantom force, as a two-turn attack, gives it even more opportunities to avoid damage and regenerate the sitrus berry. It played more or less as expected. Will-o-wisp is just a fantastic move, and often I never moved on to actually attacking things, being content to sit around and burn whatever crossed Trevenant's path.
I thought I was being so clever with this set, so it tickled me to see MD running the exact same thing!
Ferrothorn @ Leftovers
Iron Barbs
Brave
252 HP, 172 Atk, 84 Def
Gyro Ball
Thunder Wave
Poison Jab
Protect
Ferrothorn was a tough one to pin down, and in the end I made some poor decisions with it. It's very powerful in this format, as one of the few pokémon that resists poison- and flying-type attacks. Picking out only four moves was tricky. Thunder wave was for speed control, but ultimately I never used it or felt myself remotely interested in using it. It also was counterproductive with gyro ball, but gyro ball itself was rarely useful--this is such a slow format the poison jab is almost universally better, a lesson that I somehow failed to learn across the entire tournament, where I kept opting to gyro ball mega abomasnow for some reason. Why. I think running acid spray or curse over thunder wave would have been the right choice.
Although ferrothorn is usually thought of as a defensive pokémon, it actually has pretty good attack, and gyro ball really hurts faster pokémon. Poison jab gives excellent coverage in grass monotype, and is particularly helpful here because there aren't a lot of super-fast pokémon that take the hardest hits from gyro ball. Ferrothorn did a ton of work for the team and got quite a bit of damage in, which wasn't a surprise but was of course greatly appreciated.
Chesnaught @ Coba Berry
Bulletproof
Impish
140 HP, 252 Atk, 84 SDef, 36 Spd
Hammer Arm
Zen Headbutt
Feint
Spiky Shield
Chesnaught was the last pokémon on the team to be finalized. Originally I had a physical sceptile in this spot, and then I went to Virizion instead. Above all I wanted a pokémon that would be able to take on ferrothorn without a problem, and chesnaught can certainly do that. It also helps against mega venusaur, since bulletproof protects it from sludge bomb and zen headbutt does reasonable damage. I ultimately preferred chesnaught to Virizion because I thought that a bulkier pokémon complemented the team better, and as worried as I was about sludge bomb I thought having a pokémon that could demolish most pokémon using it as a primary attack would be a big help.
Most of the moves are pretty self-explanatory. I'm a big fan of feint, since it not only gives chesnaught a priority attack, it can really help to make sure that an obnoxious pokémon dies by stripping its protect/detect so chesnaught's partner can take it down. In practice the pokémon I used feint on were never protecting anyway, but they
could have been. A hot contender for this moveslot was helping hand, which works great with abomasnow in particular; I'm not sure there's anything in the format that can take a helping hand-boosted blizzard without being knocked out.