Newly Limited in September

Black Whirlwind
Royal Oppression
Infernity Launcher
Trishula, Dragon of the Ice Barrier
Monster Reborn
Dark Hole

Black Whirlwind: Whirlwind is somewhat of a problem, apparently more so in the OCG. Basically each time a blackwing is normal summoned and not stopped, your opponent will gain a potentially massive advantage. The existence of Gale, Blizzard, and Vayu to an extent plague this card's legality. If all blackwings were on par with Shibi and Breeze, then Whirlwind would be a lot less powerful. Nonetheless, it is not down to 1, so not only to BW players have to draw it, they also have to avoid all the new S/T destruction cards running around in this format.

Royal Oppression: Ouch. Really. My Koaki deck lost this and many decks are hard enough to beat with needing to draw into 2, let alone one. What's the reasoning with the banning? Well I'm sure it is a combination of a lot of things. Some people say Konami doesn't like bits of the game being shutdown(many cards stop special summons right now). Perhaps Oppression, though great in some decks, are TOO great in others. Your opponent gets the choice to stop your monsters, but if you don't play anything then there must not be much of a choice is there? Obviously, we had to replace our Oppression with Dark Hole, which loses a ton of stunning power. We'll talk about Dark Hole a little later on. I just hope a new card comes about with the stunning power of oppression.

Infernity Launcher: Having played against the new format version of this deck, I do feel it has been toned down drastically. You basically get 1 shot at a powerful, gamewinning manuever, and if it does not fire off then you have to play normally. Infernity Mirage is another Launcher, but without careful planning it could wind up in your hand and unplayable. I think I would have liked seeing infernity barrier get hit, but like I said earlier, the current game-state shows that Konami doesn't want to kill the best, unique parts on the deck, they just want to make it more fair(run on sentences ftw). I like the new infernity build. It's actually more appealing to me than the original OTK version.

Trishula, Dragon of the Ice Barrier: We won't be discussing this very much. A few decks in the OCG were able to play multiple Trishulas per turn, which depletes your opponent's hand in a sort of unfair way. Went to 1, not for any particular reason, but prevents abusive decks from spamming it.

Monster Reborn: Part 2 of Konami's "Let's have a fun format" fixes. Monster Reborn is essentially the most powerful Recursive tool in the game. There's plenty of theme specific recursion that does MORE than Monster Reborn, but as far as generic spells go, nothing targets as much as Monster Reborn with 0 cost. Many people think reviving cards from the opponent's grave will break the game, but I feel that reviving your own monsters is usually the better play. Monsters in your grave are usually 1 of 3 things. 1) A failed strategy. 2) A graveyard-based strategy to utilize later. 3)An exchange of field/hand resources. So unless it is a game-winning play, monster reborning an opponent's monster SHOULD do less for you as it would one of your own monsters(obviously special cases apply). Other than that, Monster Reborn is a must for any deck, even more than Brain Control was.

Dark Hole: Part 3 of the "Let's just see what happens" format. Dark Hole's competition is Torrential Tribute, and Torrential Tribute should be ran in ANY deck imo, even decks that run a couple of Royal Decree. But now, some of those decks that didn't need Torrential for defense, can use Dark Hole for offense, which is the difference between the 2 cards. Torrential is about 85% defense, Dark Hole is probably 30% defense, the rest is offense. You use Dark Hole to open a safe offensive, or breakthrough overwhelming odds. Many people will play Dark Hole as soon as they see a chance for an offensive, others(like me) hold dark hole as long as possible to reset an opponent's overwhelming maneuver. Both are probably equally as good of a play, and which is best is definently personal preference.