Exactly how limiting the floodgates have been varied pretty radically, from minor inconveniences to that feeling you get when you run out of the house fifteen minutes before a big interview and realize there's a boot on your tire. Without much exposure to the format or overall testing, it's hard to say exactly how strong the card I want to talk about actually is, but on paper it's incredible. Primal Origin unleashed a lot onto the dueling community, but one of the less hyped cards might be one of the most important: And the Band Played On.Floodgate Symphony
Rather than cut off Special Summoning entirely like Archlord Kristya, Vanity's Emptiness or Vanity's Fiend, And the Band Played On only blacks out Special Summoning of monsters with the same Rank or Level as the monsters you already control. Realistically, that means all Xyz Summoning's out the window, on the assumption that you can clear out your opponent's field before they can dump two Normal Summons into one Xyz Monster. If your opponent tries to Special Summon two monsters of the same Level simultaneously, And the Band Played On won't stop that either, but there aren't many cards right now that can even do that. Outside of Rescue Rabbit, Double-Edged Sword Technique and Soul Charge, the options are pretty dismal.
Soul Charge is the ultimate work-around to The Band, since it brings back monsters simultaneously, but other than the exceptionally small pool of cards that bring things out all at once like that, The Band keeps things handled pretty efficiently. Also, keep in mind that Soul Charge can't bring back monsters with the same Level as the ones you already control; that obviously only applies on an empty field.
If you really wanted to, you could use cards that alter the Levels of the monsters you control and Xyz Summon with them, but that's a lot of extra hassle for a work-around to your own card. Outside of the Armor Ninjas, there isn't a deck that conveniently goes about swapping Levels without additional commitment. Tragoedia's an option, if you're that kind of person, though.Venue's Everything
Most of the Six Samurai are different Levels, with Kagemusha of the Six Samurai at Level 2, Legendary Six Samurai - Kageki at Level 3, Legendary Six Samurai - Kizan at Level 4 and both Grandmaster of the Six Samurai and Legendary Six Samurai - Shi En at Level 5. There are some overlapping members, like Kizan and Legendary Six Samurai - Enishi, but most of the Six Samurai that overlap in Level don't have to come out together or end up getting Normal Summoned anyway. The Band won't stop Shi En from hitting the field or any of the other Synchros the deck has access to, so you can Main or Side Deck it with little to no negative repercussion. Abyss Dweller, Number 101: Silent Honor ARK and Evilswarm Exciton Knight are handy in a pinch and all have relevance in the format, but neither player having access to them while you still have your Full Salvo of Synchros is better than both of you getting to Xyz freely. Since Bujin, Geargia and other Xyz-heavy decks can't flood the field under The Band, Enishi's monster-bouncing effect's way stronger also. The general power boost from The Band is huge.
Dark World benefit in a similar way, thanks to Goldd, Wu-Lord of Dark World; Grapha, Dragon Lord of Dark World and Beiige, Vanguard of Dark World differing in Level. Playing the beatdown game behind a single Grapha isn't exactly the pinnacle of speed, but there's something to be said for The Band and Dark Smog together, ripping apart your opponent's graveyard while they fail to produce anything that can stave off a 2700-3000 ATK monstrosity. Other than multiple copies of Goldd and Sillva, Warlord of Dark World, The Band won't stop any of the Dark World monsters' graveyard effects, so you're free to draw, search and destroy at your leisure. I feel like I'm not alone in saying Dark World aren't really a "deck" so much as a Russian Roulette game with better art, but this takes the theme a step in the right direction, giving them more to do than hope they open Dragged Down into the Grave.
It's not salty if it's true.
On a more competitively relevant note, Madolche don't have many plays under The Band. The deck's big appeal is Madolche Queen Tiaramisu's insane disruptive force, with the speed and searchability that Madolche Anjelly, Madolche Hootcake and Madolche Messengelato give you. Madolche Magileine doesn't hurt either, essentially playing the part of Elemental Hero Stratos with a built-in recycling effect. While The Band's active, Madolche can't muster much more than a simple beatdown strategy under Madolche Chateau. Anjelly can search and Special Summon Hootcake, which can Special Summon Messengelato, but that's where things go sour. There's nothing that follows that play without the ability to make Leviair the Sea Dragon and bring back Anjelly for Tiaramisu.
I don't know how I could avoid bringing up Blackwings. With Blackwing Armor Master and Blackwing Armed Wing, plus Blackwing - Vayu the Emblem of Honor, there's something to be said for the deck's ability to make Synchros. Blackwing - Gale the Whirlwind has a different level than most of the Blackwings, and Blackwing - Blizzard the Far North doesn't even have another Level 2 to Special Summon most of the time. Between Gale, Blackwing - Sirocco the Dawn and Blackwing - Bora the Spear, there's swarm potential for days, and none of it's hindered by The Band. Thanks to triple Black Whirlwind and Allure of Darkness, the deck has enough speed to keep up with most things; the Blackwing problem's mostly one of low power compared to the rest of the format. With The Band knocking down Xyz Monsters and keeping same-Level swarming to a minimum, that might be enough to shoehorn them into a Regional top or pick up a locals here and there.
Not that the deck needs any helping hands, but Artifact Traptrix Hands can use The Band to play the stun game even more efficiently. Artifact Moralltach won't conflict with Ice Hand or Fire Hand, and the Traptrix don't necessarily have to be taking up room on the field at the same time. Saving the Hands until after Traptrix Myrmeleo leaves the field or vice versa removes any downside to The Band, and leaves you in a position to pick apart your opponent's field with Moralltach and Fire Hand. If your opponent has enough different levels to keep putting multiple monsters on the field at the same time, The Band wasn't going to help in the first place, but the rest of the time you'll be left with a wildly effective field-controlling tactic that doesn't have any downside for you.
Bujin take a Little Damage, essentially losing the ability to put Bujin Hirume onto the field at all unless Bujin Yamato's already left the field. If you got past Bujingi Hare and Bujingi Crane and knocked out Yamato, you're in a pretty good position anyway, though. Since every Xyz Monster in a Bujin player's Extra Deck's Level 4, dropping multiple Xyz at the same time's off the table. Add the fact that Hirume can't come out while literally any other Bujin's on the field and the pushing power of the Bujin strategy's essentially reduced to zero while The Band's up. It won't stop your opponent from Normal Summoning a second Bujin and Xyz Summoning something, but it will force them to play slower, and that's probably exactly what you want if you're running The Band in the first place.Cacophony Of Control
The Band has a wide range of playability, but still hits enough decks to be important and useful, thanks to the extreme diversity of the format. I'm not a member of Konami's R&D, so I can't speak to the exact thought process behind this card, but it seems like the perfect tool to give a boost to non-Xyz Summoning decks. If that was the idea it couldn't have been made better, save for adding in some really ridiculous additional stuff like drawing a million cards or adding all of Exodia to your hand. It has just enough text to convey the point that it's not about that Xyz Summoning life, and that Synchro Summoning should still be on people's minds. I would definitely expect to see it start popping up more in the near future.