With the release of Mirrodin Besieged, Block Constructed has a reasonable enough cardpool to be playable, and the Daily Events and Premiers on Magic Online are firing.
Having won the Premier last week, I am now clearly an expert on the format.
This is what I put together, mostly cobbled together from a couple of netdecks and played a couple of times in the tournament practice room and 2-man queues before I took down the PE.
The first thing people comment on is that Kuldotha Phoenix doesn't really have the support it needs to come back often... or ever. I've yet to bring it back, though I have had a game or two where my opponent clearly made a play to keep my artifact count down. The important thing to remember is it's not a Phoenix - it's a cheaper Volcanic Dragon.
The mana curve of the deck is rather steep - most of the cards cost 4 or 5. This is a solidly midrange deck, with the early cards mostly being used for board control. As a result, Goblin Wardriver is nowhere near as good in this deck as he would be in a deck with a lower average mana cost that gets more people on the board. His primary role is to pump up Spikeshot Elder during an attack and to serve as basically a hole-filler on the curve.
Phyrexian Revoker is another hole-filler, but one that doubles as an important role player against the Tezzeret, Agent of Bolas and Kuldotha Forgemaster decks. Those are the two cards he names most of the time, with Liquimetal Coating and Tumble Magnet showing up reasonably often.
Perilous Myr is one of the most important cards in the format, and my later drafts of this deck have gone up to the full 4-spot, moving Shatter to the sideboard. I have no idea whether this is correct, but the Myr is just incredible. He kills almost everything that matters when he dies, and forces opponents to make bad plays. You will curse when he comes down on the other side of the table, which brings us to...
Red Sun's Zenith. I think I've cast this on more creatures in the past week than I've ever done with a Fireball variant in Constructed. This exiles the creature it kills, which is huge against Perilous Myr and to a lesser extent Viridian Emissary (though I tend to prefer just letting them get the land, and saving Zenith for something more important). The deck already has tons of reach in the hasty beatsticks provided by Koth of the Hammer, Hero of Oxid Ridge, and Kuldotha Phoenix, so sitting on Zenith just to try to blow them out of the game with it is often incorrect. Clearing a Perilous Myr off the board without losing your team often allows you to get more damage in than the Zenith would ever do by itself.
The sideboard is basically a pile of useful cards that this deck can cast rather than a cohesive 75. Into the Core is basically the MVP against the Forgemaster deck, as well as the Rock deck I played against in the Semifinals (more on that later). Ratchet Bomb is trash that should be replaced by Slagstorm and/or Arc Trail for broad use, or Burn the Impure for more direct Infect hate. I've seen people running Galvanic Blast, but I'll play the Trail over that in a deck which can't metalcraft it every time. Shatter is probably overkill, and I am likely to replace the Shatters and Bombs for Slagstorm and Burn the Impure as a full changeover. Molten-Tail Masticore is essentially the replacement of one of your "preboard" cards - Phyrexian Revoker or Perilous Myr - against decks where either isn't amazing. You can also take out Hero of Oxid Ridge for the Masticore when bringing it in, to keep your manacurve relatively sane. This is, incidentally, why I really don't like Oxidda Scrapmelter. I'd like to play something before turn 4!
So, what's the metagame look like?
On the aggressive side, we have Tempered Steel and Kuldotha Red variants. That's really about it for true "Aggro."
On the control side, there are roughly 4 different Blue decks: Grand Architect Blue, [card Tezzeret Agent of Bolas]Tezzeret[/card] with Kuldotha Forgemaster, Blue-White-Black Venser, the Sojourner, and Blue-Black Consecrated Sphinx Control (with or without Tezzeret). The lines kind of blur between these, and it's entirely possible to hybridize two or possibly even three of these strategies together. Going for all four is probably too greedy.
At varying degrees of "midrange," we have straight Infect, [card Liquimetal Coating]Liquimetal Infect[/card], mono Red, and [card Glissa, the Traitor]Glissa[/card] Rock.
Architect Blue was popular pre-Besieged, but has waned somewhat as people have shifted over towards Tezzeret-centered lists. Here's a post-Beseiged Architect list:
Forgemaster Tezzeret is usually a Blue-Black deck, though White splashes are possible.
Here's a more or less stock Forgemaster list:
There's also a deck somewhere in between these two extremes, which plays Sphere, Inkmoth Nexus, Tezzeret, and Sphinx, but eliminates the Forgemaster-Blightsteel nonsense, which treats Tezzeret, Agent of Bolas as if it were a sort of hybrid of Jace Beleren and Elspeth, Knight-Errant.
Moving over to the Aggro side, let's take a look at Tempered Steel and Kuldotha Red.
There's not a lot to say about these - the decks as we know them in Standard are pretty much just the block lists with some bonuses thrown in - which is probably a large part of why they're not as successful in the larger environment. Goblin Wardriver is obviously far better in this deck than in the more powerful Big Red list that's been stomping face.
Mono Green Infect is a dumbly straightforward deck, but there's one common version that presents an interesting twist: Liquimetal Coating.
What is the saddest feeling a man can have in this block constructed format?
The one he gets when his Koth of the Hammer turns silver.
This deck gets to cheat and blow up anything so long as it has its key artifact in play - but it's still entirely functional without it! This format has so many random artifacts running around that the deck will always have things to Corrupt or Slice... except for against that aforementioned version of Blue-Black Control. On the flip side, Throne of Geth provides a nifty bonus play when you have Coating but no artifact destruction spells: sacrifice your own spare lands to Proliferate.
The Rock is the next deck on the list, and it's probably the worst matchup for mono Red.
So many 2-for-1s! Plus Bonehoard to take advantage of all the death-trigger guys that you block forever with. Mortarpod to let you do it yourself! Glissa, the Traitor to get your artifacts back when things die!
Just consider a line of play like turn 2 Perilous Myr, turn 3 Glissa, the Traitor, turn 4 Mortarpod, shoot a guy, move it onto the Myr, shoot two more guys - that's 2+1+1 damage and you get the Myr back if the last 3 involved a kill, so you can do it all over again. It's no Goblin Sharpshooter, but a creature deck is going to be really hard-pressed to beat it anyway. You can even use this to bring back a dead Wurmcoil Engine late in the game.
The sideboard even has everything, including Pistus Strike and Go for the Throat to take down Consecrated Sphinx. It's borderline impossible for Red to beat it - I got a perfect aggro curve into Sword of Feast and Famine game 2 against his Glissa, the Traitor play, followed by a game that I only won because he played a Mortarpod before combat, letting me Into the Core his Wurmcoil Engine - followed by 3 straight Kuldotha Phoenixes. It looks like the midrange infect decks would have a hard time beating this deck as well.
Obviously it's not great against Kuldotha Forgemaster game 1 and it seems weak against Blue Control decks in general, but the sideboard gives it a ton of flexibility. I feel like there's some overkill going on with the 4 Creeping Corrosion and 4 Go for the Throat and would probably shave both of those down by 1 to try to make room for something to beat Blue decks with.
If you're looking to get into the format, the first thing to look at are the key cards and interactions - as in what you're going to be up against. The format hasn't fully shaken out yet, and the Blue Control lists in particular are all over the place, so you need to be prepared for your opponents to come at you from a variety of different angles.
I've compiled a list of what I think are the most important cards in the format. I'm not trying to name every card that sees play, but the ones that are major components of one of the decks (Tempered Steel, Koth of the Hammer), fill a staple role across multiple decks (Go for the Throat), or act as unique roleplayers that don't really compare to other cards (Mimic Vat).
Black: Black Sun's Zenith, Go for the Throat, Grasp of Darkness, Memoricide, Phyrexian Rager, Skinrender, possibly Geth, Lord of the Vault and either of Carnifex Demon or Massacre Wurm. If you think Black infect is a real deck, throw in Skithiryx, the Blight Dragon and friends.
Artifact: Blightsteel Colossus, Bonehoard, Chimeric Mass, Contagion Clasp, Contagion Engine, Etched Champion, Flayer Husk, Ichor Wellspring, Kuldotha Forgemaster, Liquimetal Coating, Memnite, Mimic Vat, Mindslaver, Molten-Tail Masticore, Mortarpod, Mox Opal, Myr Battlesphere, Necropede, Palladium Myr, Perilous Myr, Phyrexian Revoker, Plague Myr, Precursor Golem, Ratchet Bomb, Signal Pest, Sphere of the Suns, Spine of Ish Sah, Steel Hellkite, Sword of Feast and Famine, Sword of Body and Mind, Tumble Magnet, Wurmcoil Engine.