Is Urza a thing of the past, simply an incredibly powerful deck for the history books? No way.
It's true that the latest round of bannings impacted Simic Urza decks significantly, costing them both Mox Opal and Oko, Thief of Crowns. Now the deck has had a few weeks to rebuild as players start to try and find new cards to replace the banned ones, and it turns out that without Oko, there isn't as big an incentive to play green anymore.
The current most popular version of Urza is actually straight Dimir, as we have seen the archetype at the top of the standings in multiple Opens over the past couple weeks. Here is Eli Kassis's version.
Without access to Mox Opal the deck does lose some of its explosiveness, as you are forced to rely on slower pieces of acceleration like Talisman of Dominance. There are no longer any copies of Emry, Lurker of the Loch. A lot of the power behind Emry was the ability to play it as early as turn one, and without as many zero-mana artifacts in the deck that becomes far less likely. Also, without Engineered Explosives to bring back from the graveyard, Emry loses some of its power. The deck has become a bit less of a pure combo deck, and more of a Dimir Control deck, with a game-winning artifact package, that can grind out late games.
The black gives you access to disruption in the form of Thoughtseize, Inquisition of Kozilek and Fatal Push, which also gives the deck plenty of options starting on turn one. Drown in the Loch keeps popping up, and we see a copy here as a nice flexible option. The one-ofs are interesting choices, as Deprive works really well alongside Mystic Sanctuary. With more one-for-one removal and discard spells your topdecks are worse, so having Mystic Sanctuary as a way to set up your draws in the late game is quite important. The two copies of Field of Ruin are a little bit awkward alongside the three copies of Mystic Sanctuary, so you really need to think about appropriately sequencing lands with the deck.
Since this is a Whir of Invention deck you would think there would be more one-of artifacts. Actually, there aren't a ton of tutor targets because you are normally going to be looking for Thopter Foundry or Sword of the Meek to close the game out. This two-card combo works really well alongside Whir of Invention so that you can find them when needed, but often you won't want to naturally draw a card like Sword of the Meek. Pithing Needle and Nihil Spellbomb are reasonable cards in most matchups, so while you can Whir for them, they are fine as natural draws as well. On the other hand, Grafdigger's Cage is very matchup specific, so it makes sense for that to come out of the sideboard.
Besides the Thopter/Sword combo to make a ton of Thopters, there is of course Urza, Lord High Artificer itself as a way to close out games. The countermagic package of Archmage's Charm and Cryptic Command works here because the deck retains a very blue mana base, and these are the cards you are most likely to want to buy back later with Mystic Sanctuary, besides Whir of Invention.
The sideboard allows you to pick and choose what matchups you want to target. Right now, with Amulet Titan being so popular, I like having two copies of Ashiok, Dream Render —one of the best cards in the format to fight Primeval Titan decks. Stopping Summoner's Pact is even more important than the Primeval Titan triggers themselves. Also, being able to mill away your opponents' key combo pieces is really nice, and I expect to see plenty of Ashiok, Dream Render in the sideboard of a variety of decks moving forward.
This deck wants access to some amount of creature removal and life gain, and Battle at the Bridge is the perfect fit. Ceremonious Rejection isn't normally a card you see three copies of, but it's there to respect Tron decks, which otherwise are very scary matchups. I like what the deck is doing, and it really does have game against everything.
The next deck I'm going to talk to is technically an Urza deck, but shows just how crazy you can take Urza if you want to. This deck, that Ryan Bennett took to the Top 4 of last weekend's Modern Classic, is much more combo forward:
Both Grixis and Dimir share a few cards that are essentially must-plays in any Urza deck. Those cards are Urza, Lord High Artificer, Mishra's Bauble and Arcum's Astrolabe. Every Urza deck needs some number of cheap artifacts. Mishra's Bauble and Arcum's Astrolable are the best ones since they replace themselves while providing an extra benefit. This Grixis Urza deck also plays the Thopter/Sword combo, but that is where the similarities end. This is a very different deck.
Adding the red is actually a pretty low cost, especially if you don't have a card like Archmage's Charm in the deck. With fetchlands and Arcum's Astrolabe, the mana is quite reliable. There is even a single copy of Pentad Prism to help with fixing and acceleration. But why play red at all? For one card: Underworld Breach. As soon as you see Underworld Breach it should be apparent that filling up the graveyard is a very important part of the deck.
Underworld Breach is incredibly powerful if you are able to abuse it, and this deck can. You can play what I call a "value Breach." Too often players assume you need to win the game the turn you play Underworld Breach, but that isn't the case. With the various zero-mana artifacts in the deck, actually playing spells from the graveyard is often not going to have a mana cost. Even so, the deck is designed to be able to win all in one turn too, so let's go through how that might happen.
In order to truly abuse Underworld Breach you need some self-mill, like we have seen in the Lotus Breach deck in Pioneer.
Emry, Lurker of the Loch: This is the most obvious enabler as it has seen play in Urza decks before, so we are already aware it is just a good card in the deck. This deck also plays more cheap artifacts compared to the Dimir Whir version of the deck, so rebuying something like Engineered Explosives is a possibility here. Furthermore, there are also two copies of Mox Amber, making Emry even more important. Mox Amber is high variance because without an Urza or an Emry it's not going to produce mana, but the upside is there. Having access to zero-mana acceleration is a big deal, and in a world without Mox Opal, this is the next best thing.
Grinding Station: This is the more important mill card in some ways because it is reusable, and allows you to realistically mill through your entire deck in one turn. Untapping the Grinding Station consistently is actually pretty easy (I will get into the best way to do that), and this is what makes the Underworld Breach plan possible. Thassa's Oracle lets you actually win after milling your deck, though you can also mill the opponent with Grinding Station as well.
There are a bunch of cheap artifacts in the deck, so especially if you are able to get Urza onto the battlefield it becomes much easier to have extra mana to continue to cast artifacts from your hand as fodder for the Grinding Station. However, this is actually milling "the hard way."
If you're looking to pick up the deck right away, this section will help you understand exactly how it all works.
Games can play out in a variety of different ways, so I personally like to keep most opening hands with the deck, rather than mulliganing for a specific combo piece. This is counter-intuitive compared to most combo decks that are looking to find something specific, but because there are multiple different combos, you don't have to look for the same one every single game.
Keep in mind that Underworld Breach can allow you to cast a combo piece out of your graveyard if you do end up milling it, or have it in the graveyard for some other reason.
Urza + Thopter Foundry + Sword of the Meek
Let's start with the combo you are most likely to be familiar with by now, the same one as in the Dimir Urza deck. This combo allows you to get infinite life and Thopter Tokens. Having Urza in play allows you to tap Sword of the Meek for a blue mana, and that mana can be used to sacrifice the Sword of the Meek to Thopter Foundry which will create a Thopter Token. Sword of the Meek will then return from the graveyard, so rinse and repeat from there!
Grinding Station + Underworld Breach + any zero-mana artifact
This will allow you to mill your entire library. After you mill three cards with Grinding Station, you can then exile those to bring back the zero mana artifact, which can then be sacrificed to Grinding Station again because Grinding Station will untap when the zero mana artifact comes back into play. This will lead to a win with Thassa's Oracle, but in order to do that you do want to have at least three additional cards in your graveyard to be able to cast it with Underworld Breach if it gets milled. Sometimes you will also need more than three cards in the graveyard to recur Mox Amber from the graveyard for some additional mana to cast Thassa's Oracle.
Grinding Station + Sly Requisitioner
Sly Requisitioner is a card that hasn't seen much Constructed play, but works really well in this deck as a very important combo piece. Having Grinding Station and Sly Requisitioner in play means that Grinding Station can sacrifice as many nontoken artifacts as you want that are already in play, without needing to play more artifacts to untap the Station. These two cards by themselves do not create infinite self-mill, because the tokens created by Sly Requisitioner, if sacrificed, will not replace themselves.
Grinding Station + Sly Requisitioner + Sword of the Meek
This is actually straight-up infinite mill. You do not need to mill yourself at all, you can instead mill out the opponent. Each time you sacrifice the Sword of the Meek to the Grinding Station you create a 1/1 from Sly Requisitioner, which continues to bring back the Sword of the Meek.
Besides these combos, many of the cards just work well together. For instance Sly Requisitioner is kind of like Urza in that it is a reasonable card to simply have on the battlefield to potentially generate some Servos which could be useful later, and also the additional artifacts it provides give you more mana with Urza.
The way you want to start the game is with some cheap artifacts, and then use one of the payoff cards like Urza or Underworld Breach to generate a big advantage that can quickly chain into a win. The cards that aren't good in your opener are multiple copies of the same combo piece, or Thassa's Oracle (generally speaking), but often you will need to keep hands that need help getting there in some fashion.
Both Urza decks are very different, though I believe the second is both more powerful and more vulnerable. By relying more on your graveyard to win, you open yourself up to graveyard hate. However, the Grixis Urza deck is very fun to play, and I'm still learning all the different combos and interactions that are going on in it. I like that there are cards like Nature's Claim and Echoing Truth in the sideboard to answer any opposing hate you might run into.
It should be interesting to see which version of Urza ends up rising to the top, as clearly there is still room for innovation around this powerful artifact-based shell.