Preface: This is for the 5-player circle format (where players are restricted to attacking either a planeswalker, or the the player to their left.)
As you read please keep in mind that this deck works well in the 5-player meta, and you can tailor the threat/removal cards to your meta, but I really just wanted to share what my group has found to be a really strong deck that has a lot of beautiful synergies.
I've been playing this at my kitchen table game and it has been consistently doing very well even when my friends pilot the deck. This deck works best when there are no other counter-spell decks at the table and some of your opponents are wiping the board every few turns with Wrath of God effects. If someone is doing that, and you draw some of your own disruption, you won't die to a fast deck.
You draw so many cards, play so many lands, then shuffle your instants/sorceries into your library, that you end up drawing nothing but disruption + threat cards late game, while your opponents don't keep anything on the table without your permission.
This deck reliably survives early game with all the disruption cards, but shines late game when you've drawn all the lands out of your library, and shuffled all of your threats and disruption cards back into the library. After you have godly amounts of mana, and have nothing in your library each turn but more counterspells and cyclonic rifts, you can end the game with a 23/23 inkmoth nexus+lashwrithe with haste, flying, and infect.
The deck can reliably combo reassembling skeleton with Lashwrithe and 2 Diamond valley to gain about 46 life a turn!
This deck is really built around burgeoning. Burgeoning is a very powerful card I've been playing with lately. It gives decks early and late mana ramp, and can be played turn one. Running as a 4-of is good in any deck that can play green mana untapped on turn one. But it works best when you have as many lands in your hand as the rest of the table put together. That means you need a lot of card draw, or a lot of dumping lands into the graveyard and then into your hand, or directly into your hand. Early card draw is essential in every deck though, and especially when you start the game without burgeoning (so that you can draw it!), so your card draw has to be affordable early-game, without benefiting from burgeoning's ramp.
In short, a burgeoning deck needs as much low-mana-cost card-draw as you can get.
For card-draw, nothing comes close to blue. Mystic Remora and Rhystic study are two of the best, and cheapest, card-drawing cards in the game. These both benefit from the multiple opponents playing lots of CARDS per turn, and burgeoning benefits from lots of lands being played each turn. If we know that we want enemies to play lands and cast spells, let's make our opponents draw cards!
Cyclonic Rift is beautiful with those enchantments because it gives opponents spells to re-play so that you draw more cards! If they're struggling to keep playing their threat and defense cards because of bounce spells, they usually can't afford to pay the cost for mystic remora or rhystic study. Basically it makes your card draw enchantments fill your hand faster, because people will be re-playing their expensive cards, and won't spend the additional mana to keep you from getting card-draw.
Day's Undoing has several important effects:
1) it is another card-drawing spell to help you dig through your library to draw to complete the Burgeoning + Mystic Remora Combo.
2) it messes up reanimator decks and decks that rely on the graveyard zone.
3) it protects you from milling.
4) If an opponent does play an uncounterable threat card, Cyclonic rift can bounce it, then Day's Undoing can make them shuffle it into the library, but leaves them with some lands and cards to play, meaning you will be able to play your lands, and draw cards off of their plays, and if you draw a land you'll probably be able to play it too.
5) it gives your opponents each 1 or 2 land cards to trigger your burgeoning.
6) It cycles all of your used up counterspell, bounce, and threat cards back into your library, making your next "draw a card" effect give you something powerful.
Thanks to the mana ramp, card draw, and making people replay the same spells, you get massive card advantage.
In summary, blue rocks with burgeoning thanks to the card-draw, and the your card-draw benefits from the mana-ramp, and lastly disruption from Cyclonic Rift, or Day's Undoing synergize with both, and each-other, making the whole greater that the sum of its parts.
As you read please keep in mind that this deck works well in the 5-player meta, and you can tailor the threat/removal cards to your meta, but I really just wanted to share what my group has found to be a really strong deck that has a lot of beautiful synergies.
I've been playing this at my kitchen table game and it has been consistently doing very well even when my friends pilot the deck. This deck works best when there are no other counter-spell decks at the table and some of your opponents are wiping the board every few turns with Wrath of God effects. If someone is doing that, and you draw some of your own disruption, you won't die to a fast deck.
You draw so many cards, play so many lands, then shuffle your instants/sorceries into your library, that you end up drawing nothing but disruption + threat cards late game, while your opponents don't keep anything on the table without your permission.
This deck reliably survives early game with all the disruption cards, but shines late game when you've drawn all the lands out of your library, and shuffled all of your threats and disruption cards back into the library. After you have godly amounts of mana, and have nothing in your library each turn but more counterspells and cyclonic rifts, you can end the game with a 23/23 inkmoth nexus+lashwrithe with haste, flying, and infect.
The deck can reliably combo reassembling skeleton with Lashwrithe and 2 Diamond valley to gain about 46 life a turn!
4 burgeoning
4 mystic remora
4 day's undoing
4 rhystic study
disruption:
4 cyclonic rift
3 force of will
2 Time Stop
2 lashwrithe
1 riftsweeper
1 emrakul, the aeons torn
1 reassembling skeleton
1 glistening oil
utility lands and land fetchers:
2 sylvan scrying
2 diamond valley
2 inkmoth nexus
1 urborg, tomb of yawgmoth
3 cabal coffers
1 ghost quarter
lands with color:
2 vesuva
4 Botanical Sanctum
4 Simic Growth Chamber
4 Hinterland Harbor
4 Breeding Pool
This deck is really built around burgeoning.
Burgeoning is a very powerful card I've been playing with lately. It gives decks early and late mana ramp, and can be played turn one. Running as a 4-of is good in any deck that can play green mana untapped on turn one. But it works best when you have as many lands in your hand as the rest of the table put together. That means you need a lot of card draw, or a lot of dumping lands into the graveyard and then into your hand, or directly into your hand. Early card draw is essential in every deck though, and especially when you start the game without burgeoning (so that you can draw it!), so your card draw has to be affordable early-game, without benefiting from burgeoning's ramp.
In short, a burgeoning deck needs as much low-mana-cost card-draw as you can get.
For card-draw, nothing comes close to blue.
Mystic Remora and Rhystic study are two of the best, and cheapest, card-drawing cards in the game. These both benefit from the multiple opponents playing lots of CARDS per turn, and burgeoning benefits from lots of lands being played each turn. If we know that we want enemies to play lands and cast spells, let's make our opponents draw cards!
Cyclonic Rift is beautiful with those enchantments because it gives opponents spells to re-play so that you draw more cards! If they're struggling to keep playing their threat and defense cards because of bounce spells, they usually can't afford to pay the cost for mystic remora or rhystic study. Basically it makes your card draw enchantments fill your hand faster, because people will be re-playing their expensive cards, and won't spend the additional mana to keep you from getting card-draw.
Day's Undoing has several important effects:
1) it is another card-drawing spell to help you dig through your library to draw to complete the Burgeoning + Mystic Remora Combo.
2) it messes up reanimator decks and decks that rely on the graveyard zone.
3) it protects you from milling.
4) If an opponent does play an uncounterable threat card, Cyclonic rift can bounce it, then Day's Undoing can make them shuffle it into the library, but leaves them with some lands and cards to play, meaning you will be able to play your lands, and draw cards off of their plays, and if you draw a land you'll probably be able to play it too.
5) it gives your opponents each 1 or 2 land cards to trigger your burgeoning.
6) It cycles all of your used up counterspell, bounce, and threat cards back into your library, making your next "draw a card" effect give you something powerful.
Riftsweeper is there because you pretty much can always benefit from bringing back one of your exiled creatures, time stop, day's undoing, or a Mystic Remora that you pitched to cast force of will.
Thanks to the mana ramp, card draw, and making people replay the same spells, you get massive card advantage.
In summary, blue rocks with burgeoning thanks to the card-draw, and the your card-draw benefits from the mana-ramp, and lastly disruption from Cyclonic Rift, or Day's Undoing synergize with both, and each-other, making the whole greater that the sum of its parts.
Tax-Rack with Blade of Selves
Tax-Rack with Vicious Shadows
Mesmeric Orb + Lord of Extinction
G/W/K Sun Titan Reanimator
U/G LashWrithe