I guess I'll be the first to post a decklist for the dreaded Rainbow deck! Mjack has mentioned having a very consistent list for Conflux, but I think mine might still be a cut better! Definitely not the most meta choice, but I believe it is still a competitive one.
My inspiration for this Counterlash deck comes from the friction between ideas among 2best and Hakeem. Hakeem's idea for Counterlash was a fatty ramp deck that appreciated the counterspell support. However, I agree with 2best's sentiments on a single pitfall: Opting to not play your 6-drop in hopes of Counterlashing out an opponent was unreliable and clumsy. Instead, I wanted a Counterlash deck that played to some of blue's best assets: Card draw and bounce.
Card draw helped get the pieces of your play together (A fatty and Counterlash, along with 6 land) while bounce helped ensure you would be able to play it out. Bounce is also extremely crucial early on for stalling your opponent out. To this effect, I built off of 2best's original Counterlash deck but wanted to expand upon and refine it.
Before 2015 came out, another user's deck list helped inspire me. I think Jalira has been flying pretty low under the radar so far, but I think she is the other angle this deck needs beyond stall. So thank to Djampnz for this inclusion!
(Premiums) RainbowMana Base:4 x Izzet Guildgate
12 x Island
8 x Mountain
Creatures:2 x Jalira, Master Polymorphist
2 x Talrand, Sky Summoner
2 x Siege Dragon
1 x Inferno Titan
1 x Charmbreaker Devils
1 x Maelstorm Archangel
Other Spells:4 x Vapor Snag
4 x Voyage's End
4 x Krenko's Command
3 x Negate
4 x Think Twice
3 x Dissolve
4 x Inspiration
2 x Counterlash
This mana base is mostly arbitrary, and was decided mostly on game-by-game random tweaking. Help me I don't know how to accurately decide mana base Ten hours in the air between Japan and Canada make for good testing time. This deck was originally Red/White/Blue for Raise the Alarm and even Brimaz, but I ultimately found myself needing the extra bounce provided by Voyage's End and I don't really miss the extra tokens. I fear that this is one deck that comes together better in game than on paper, so I'd like to implore you to try it-- however, I'll defend it the best I can here.
The powerful card draw of Blue really ties this deck together. It ensures you can get Jalira, Talren, Krenko's Command, or Counterlash and a fatty to make up for the thin lines of just about everything and the cohesive nature of the deck. I wouldn't cut a thing from the draw mechanic. In game, at least two of these pieces come together quite often thanks to their natural synergy. With Think Twice in the early game, it's not hard to find both Counterlash and a red fatty. Scry will also become your best friend- sometimes an early Voyage's End or Dissovle is worth it to ensure you hit your land drop or to boost your chances of topdecking the piece you need.
My original complaint with Counterlash builds is a very strong lean on a 2-of, 6-drop. It's not very forgiving should you miss those valuable pieces. With Jalira and Talren from Djampnz deck, you now have multiple strategies in the case something doesn't work. Negate is included to help defend your board once you've established presence. Especially nice for keeping Jalira or that new fatty on the board. I originally ran Nullify, but with the amount of bounce we run and the option to Dissolve, I found it unnecessary. I am still debating whether I want to cut a single Negate for a Nullify or other single card, so suggestions are appreciated.
Fatty choice explanation:
Running red fatties instead of black, green, etc. gives you the option of hard casting them. Being able to manually drop a big body was a very important decision to allow the deck even more flex in tight situations.
2best served as catalyst for why I worked on this deck in another way as well. I completely agreed on his remark that the Devils lack a lot of impact when they come in. Too often they eat removal or start to recycle spells too late to be of any use. This got me thinking about using Counterlash/polymorph to cheat them in for the beginning step, and what other kind of cards benefit from their beginning step abilities, mana abilities/monstrosities, or on-attack abilities that are normally expected to be activated the turn after they come in. Being able to cheat around this along with a virtual haste can make some already powerful cards extremely impactful the second they get play.
x1 Charmbreaker Devils: This is the card that started off my chain reaction of ideas and collaborations, in effort to make it more useable. Despite that, I now consider the Devils to be one of our weakest fatties in this deck. This is simply because of the large focus our spell pool has on card draw and cheap bounce, you're not going to be re-playing Shock or Bolt every turn. When the Devils dredge up a late game Inspiration, you're very thankful, but most of the time it is the considerably less exciting Vapour Snag. I think of the Devils as more of a finisher-- when Lashed or polymorphed into, the virtual haste for next turn and a completely untapped mana pool gives you your opportunity to strike for massive damage. In the event the Devil does bring back a lowly Vapour Snag, it is another chance to continue clearing the board and ensure you can hit for the full 8, 12, 16 damage.
Inferno Titan: Probably self-explanatory at this point. Everyone knows what a killer this guy can be. The extra clear against weenie decks (Since our nonbo's prohibit the use of Anger of the Gods) is reason enough, but Counterlashing or polymorphing into him on your opponent's turn lets him deal with the newest, most current threats, and attack again for another 3 dividable damage right away. Never underestimate the virtual haste that comes from our indirect means of summoning!
x2 Siege Dragons: I originally ran just a single Siege Dragon and two of the Devils, but I see the error of my ways now. Just like Inferno Titan, this card is a behemoth when he gets to attack. Another failsafe against the popular white weenies or even Spider Spawn match-up but just a good body on it's own. This guy does a lot when Counterlashed or polymorphed in- He gets rid of pesky walls, he's going to get rid of chump blockers, and he's going to hopefully goad a flyer into chump blocking. If there were more copies of this card, I'd happily cut Charmbreaker Devils to fit it in.
Finally, Maelstorm Archangel:
Far from a gimmick, I had actually already selected this card before even realizing it made the deck eligible for Rainbow. It was when I exited the deck editor and saw all the mana symbols beside the deck box that I realized it.
Though our only uncastable, this rogue choice let's us do something with the fatties that start to build up in your hand. With just five big guys, Jalira really hates to see them start to clog the hand. Counterlashing or polymorphing into the Maelstorm let's us put those "dead draws" to use again. Another card with an on-attack ability that likes the virutal haste and your opponent's tapped out mana, it's very easy to 2-for-1 with this card when it hits the field and will often run away with the game. And what's more, it's got flavour! My favourite thing about this deck (And other Counterlashers, like 2best and his lucky Griselbrand >:P) is the ability to sub out the fatties for whatever strikes your fancy.
Interesting note: You really should heed probability when you are polymorphing for your fatty. With just five possible outcomes, it can be very easy to estimate your chances of getting the card you most need. If there is a Charmbreaker in your discard and a Siege Dragon in your hand, your polymorph will yield either an Inferno Titan, another Siege Dragon, or the Maelstorm Archangel. Scrying also gives you a (slight) chance at getting choosy on your next polymorph.
Knowledge is power!
While I personally place a high value on the flexibility of this deck, (such as the option to hard cast) a more combo-oriented players might want to look into cards like Rune Scarred Demon, Pelakka Wurm, or even Griselbrand if you don't mind the nonbo with Jalira. And consider living the dream of Counterlashing/polymorphing into Maelstorm Angel, untapping your mana, proccing the Maelstorm to play out a Soul of Ravinca, and then drawing 5 at no life cost! (Though that's probably overkill.)
I hope you enjoyed reading my thought process on this community-assisted deck and may give it a try.