After I found out I couldn't go to Miami I started testing under banlist changes my friends and I thought could happen and while we certainly didn't expect things like Sangan banned, we did get Zenmaighty banned + Magician limited to 1 right! Of course after the actual banlist came out we tested what felt like endlessly and it's pretty apparent that the top decks are Water, Fire and Rabbit. Of course Dark World gets stronger too, not just because of Mind Crush - which I think is bad in the DW deck anyways - but because the easy Shock Lock is gone and because all the other decks got weaker. It happens every format and it might claim a couple spots at YCS Austin but it won't do anything past that. Maybe people actually learned their lesson from YCS Toronto last format and will actually prepare for it and none will top. Only time will tell on that one, but I've been pretty successful playing in the new format so far so I figured I'd share my thoughts on how the list changed the game.
Of course this would be the deck I talk about first and it'll probably be the last time. This deck has been erased from Tier 1 competitive Yu-Gi-Oh. 3 Rabbit 3 Factory still gives it a pretty good grind game but it can't compete with Water and Fire at their full power. Even when you get Rabbit + Factory, it's hard to get a Rabbit in the grave for you to use with Rat. Mage-Shark is hard to come by and that's what put targets in the grave. You have to do something like Rabbit for Rabbit, use those to search for Mage + Shark then use those to search Rat and go off. That's super slow and you aren't applying any pressure to your opponent so chances are they can kill you before your push.. or just stop your push or just have the MST for Factory and stop it all. Wind-Up Shark is also a questionable card to run at 3 copies since they aren't really doing anything until you draw Magician. Summoner Monk is starting to pop up in lists for easy Magician access but after the first night of testing with Wind-Ups it came out of my list. It's way too much to ask for to have Monk, a spell you actually want to discard (hardly ever happened and I was even running Upstarts), and Shark. Meanwhile until you gather up the 3 pieces those cards just sit dead in your hand. The best way to play Wind-Ups is probably with a Rabbit beatdown strategy with a ton of traps including cards like Compulsory Escape Device. Photon Sabre Tiger is a card I messed around with to help xyz plays with the Rabbits to get them in the grave and it was alright but this will most likely be a Tier 2 deck no matter what direction you take with it. "Goodnight, sweet prince".
At first glance Rabbit seemed to be a really strong pick especially since it can main Macro Cosmos and just outright win if the Rabbit player sees it against Water. This is the deck that got hurt the most by the Sangan ban. At full power the deck essentially had 7 copies of Rescue Rabbit (3 Rabbit, 3 TGU, 1 Sangan), last format it had 5 (2 Rabbit, 2 TGU, 1 Sangan), but this format it has a measly 2 copies. If you thought drawing normals over Rabbit was bad before it's going to be a whole lot harder to get to Rabbit now. On the subject of Macro I don't like maining the card, and if you do I think 3 is the best number. Macro is obviously only good before your opponent starts going off so you want to open with it. Opening with 2 copies is even better because it's a card that allows you to just win while it's face-up so you shouldn't really care if you have an extra dead one. It's actually better than just drawing 1 because even if they have/draw into MST you just flip the other one and win anyways.
Then you have to think about the decks Macro doesn't touch. It kind of hits Fire by negating their effects but they can still make exceeds and just beat you down with monsters + removal if you don't have the right cards to go with your Macro. In the mirror it doesn't even hit Sangan and hand traps aren't very popular right now so I mean you might get to stop a Monster Reborn but even that is unlikely. Running a card that is only really good against 1/3 matchups if you open it and if they don't have the MST isn't something I agree with. This killed Dino Rabbit in my mind because I thought the Macro variant was the only viable one. It'll still top and do well at events but you're going to have to get pretty lucky with your draws or matchups. Either main Macro and draw it at the right times or don't and face a gauntlet of Water you can't swim out of.
This deck went from hyped to flop to hyped again. After only 1 topped in YCS Miami people started to disregard the deck but double the amount of Fire Fist topped YCS Bochum than Water and it's definitely a force to be reckoned with. It's probably my favorite deck moving forward into the new format. You can go the Dragon route and get free plusses off your Fire Formation activations or just play 1/1 or go completely Dragon-less. Both versions are good in my mind for different reasons. If you play minimal Dragon/Tensen/Tenken then you don't have to worry about drawing them and can have more cards that actually do things. On the other side of it, Rank 4s are really incredible right now and Dragon gives you even easier access to them. Abyss Dweller shuts down Water, Maestroke is really good against the Fire Fist mirror, and Utopia is really good against Water believe it or not. I think there was a game in the Elijah Gersten VS Billy Brake feature match where Elijah just won off Utopia's 2500 ATK. Huge attack is really good against Water and having a searchable +1000 ATK trap card is pretty cool for that matchup. I personally run a Dragon-less build and have been enjoying not having to draw Tensen but it's all preference. Reborn Tengu is a huge reason to consider playing the deck. It's a huge card in both the mirror and against Rabbit and it's even searchable through Tenki. I think not running Tengu is incorrect.
Mono Mermail - The most hyped deck right now since Billy and Jeff recently did so well with it. Gaios + Squall seems eerily familiar.. Rabbit + Tour Guide anyone? The fact is that while the deck is really good, the surprise factor helped a lot in the deck getting 3rd place. No one was prepared for the plays the deck could make and they were able to take the event by storm. Now it's a totally different ball game. People are starting to test Breakthrough Skill more seriously for its ability to negate a Mermail effect then just sit in the grave and make Abyssgaios irrelevant. Being good against Rabbit is a plus as well and I think the card is going to catch on. Removal is also going to be big in the new format since Wind-Ups were the only deck those cards were really bad against and now people don't have to worry about that. I don't think this will be the reigning Water deck of choice come March 1st.
Undine Merlanteans - THIS in my opinion is going to be the Water deck to fear next format. The access to Dragoons and Moulinglacia is nuts and drawing Controller really isn't that bad. I'm sure you've heard it before but the synchro plays Controller offers to the deck is nuts. It gets a lot crazier when those Controllers, and in turn synchros, are free. Dumping Infantry is an easy way to destroy Abyssgaios and having Undine as Abysspike targets makes the card a lot better. I think you can probably play a Gunde in here if you want but the standard Water deck from before Abyss Rising is really powerful right now. No new cards needed.
Whatever the case, try to enjoy the format right now because in a couple months things are going to get crazy. Divine Judgment, Evilswarms, and more are going to make the game really dumb but right now it feels like real Yu-Gi-Oh so enjoy it while it lasts. There's a lot of room for innovation right now and the people that take advantage of that fact are going to succeed.