Breaking Theros: Beyond Death—Underworld Breach
Some cards are immediately recognized as broken (or at least potentially broken) almost as soon as they are previewed. For other cards, it takes months or even years before their potential is realized. Underworld Breach is certainly in the first group. You could almost hear the collective gasp of Legacy players when the card was previewed. The excitement around Underworld Breach's combo potential makes sense, considering that the two easiest comparisons are Yawgmoth's Will—a card banned in Legacy and restricted in Vintage—and Past in Flames, which has driven Storm combo decks in both Legacy and Modern. Everyone knows the card has the potential to be good and maybe even broken. The only question is how to build a deck to harness its power.
Underworld Breach asks us to do four things: first, we have to have two mana to get it on the battlefield. Second, we need a way to stock our graveyard with cards to exile to the escape mechanic. Third, we need enough mana to escape as many cards as possible from our graveyard. Finally, since Underworld Breach sacrifices itself on our end step, it wants us to win the game on the turn when it comes into play. Of course, these requests aren't independent, and ideally, the cards we use to answer one question will at least be somewhat helpful in answering the others as well, all while avoiding the trap of playing a bunch of "bad" cards to make our combo work. The reward for meeting these four requests is an extremely fast combo deck, a deck that can quite literally win the game as early as Turn 1.
Getting Underworld Breach onto the Battlefield
While we can simply wait until Turn 2 to cast Underworld Breach, getting Underworld Breach onto the battlefield on Turn 1 is actually pretty easy in Legacy. Rite of Flame is one of the best options since we can escape it for more mana once we get Underworld Breach onto the battlefield, making it a card that helps to answer two of our four questions. Lotus Petal is another very strong option since it not only adds an extra mana but also ends up in the graveyard to fuel our escape plan. After Rite of Flame and Lotus Petal, things become a bit more questionable. Chrome Mox and Simian Spirit Guide are probably the two next best options for powering out Underworld Breach on Turn 1, although both are worse than either Lotus Petal or Rite of Flame since they don't end up in the graveyard to fuel our escape plan. Since we don't really need our mana to be repeatable since we're planning on winning the game on the turn when we cast Underworld Breach, Simian Spirit Guide is probably a bit better than Chrome Mox since we don't have to exile an extra card from our hand. With four copies each of Rite of Flame, Lotus Petal, and Simian Spirit Guide, we're over 80% to have at least one in our opening hand to facilitate a Turn 1 Underworld Breach.
Filling the Graveyard / Mana to Escape
After we get Underworld Breach onto the battlefield, making oodles of mana to escape cards in our graveyard actually becomes quite easy with the help of Lion's Eye Diamond. Once we have an Underworld Breach, Lion's Eye Diamond is a Black Lotus since discarding our hand isn't really a drawback when we can cast whatever we want from our graveyard. This leaves us in a position where we can exile three cards from our graveyard to escape Lion's Eye Diamond into play, sacrifice it to make three mana of any color with no drawback at all, and then, assuming we can keep filling our graveyard with cards to exile to escape, do this over and over again, making a semi-infinite (eventually, we'll run out of cards in our deck and graveyard to pay for escape) amount of mana, which should be more than enough to close out the game.
Filling the Graveyard / Winning the Game
Brain Freeze is basically the cheat card that makes our entire deck work. For just two mana, it mills a player for three cards, but thanks to the storm mechanic, it will often be milling six, nine, 12, and eventually many more. Using our Lion's Eye Diamond mana, we can escape Brain Freeze by exiling whatever we happened to discard to Lion's Eye Diamond to target ourselves to mill at least nine cards (three from casting Underworld Breach, three from casting Lion's Eye Diamond, and three from Brain Freeze itself). Then, we can use the cards we mill to escape Lion's Eye Diamond a few more times, upping our storm count further, and then cast Brain Freeze targeting ourselves a second time, this time to mill at least 18 cards. Basically, we can repeat this process until we mill all (or essentially all) of our deck. After our graveyard is good and full, we can escape whatever we want to continue to up our storm count and then eventually turn Brain Freeze on our opponent to mill their entire deck. This leaves us with a core of a deck that looks something like this (disregard the Islands and Mountains; we'll improve the mana base later).
While this core looks extremely explosive and good at winning the game on Turn 1 if we have a strong opening hand containing Lion's Eye Diamond, Underworld Breach, and Brain Freeze, it's lacking in consistency. Thankfully, we still have 22 slots left in the deck to help shore up this weakness.
Adding Consistency
One of the easiest ways to increase consistency is to add some tutors to our deck, and because we really don't mind having cards end up in our graveyard since we're going to be able to escape them into play anyway, Gamble is the perfect tutor for an Underworld Breach deck. If we don't have an Underworld Breach in our opening hand, Gamble can find us one for just a single mana (although there is a slight risk that we discard it, it's a risk that's worth taking). More importantly, after we have Underworld Breach, we can escape Gamble from our graveyard to tutor up whatever combo piece we happen to be missing. Post–Lion's Eye Diamond, we'll be empty-handed, which means Gamble will actually play more like Entomb (tutoring the card into our graveyard since it will be our random discard). But thanks to Underworld Breach, that's fine—being in our graveyard is just as good as being in our hand. Another possibility is splashing into black for literal Entomb, but since Entomb can't ever tutor Underworld Breach to our hand, Gamble seems close to strictly better in our deck.
Another easy way to increase consistency is cheap cantrips, with Brainstorm, Ponder, and Faithless Looting being the best of the bunch. Faithless Looting is especially powerful in our deck since it gives us another way to stock our graveyard with cards while also filtering through our deck to find our important combo pieces. If we're fairly confident that we'll be able to resolve Underworld Breach, we can even loot away combo pieces like Lion's Eye Diamond and Brain Freeze since they function just as well from our graveyard post–Underworld Breach. Adding Gamble and 10 cantrips to increase consistency brings us up to 52 cards total, making the deck look something like this:
The Final Eight Slots
The final eight slots are by far the most challenging to fill. In its current form, our Underworld Breach deck is both fast and consistent, but it still has one major issue: Force of Will. While we should be good at putting our opponent to the Force of Will test very early in the game, perhaps as early as Turn 1, we are in big trouble if our opponent does have Force of Will to counter Underworld Breach since it will probably take us a while to find another copy of Underworld Breach, and without Underworld Breach we're going to have a difficult time winning the game. Thankfully, Core Set 2020 brought with it the perfect way to protect our combo from Force of Will (with the added bonus of protecting our Underworld Breach from cards like Assassin's Trophy and Abrupt Decay): Veil of Summer.
Adding four copies of Veil of Summer should go a long way toward allowing us to beat [[Force of Will]. If that's not enough, we could consider playing Defense Grid or even our own copies of Force of Will, but for now, we'll go with just the four copies of Veil of Summer to leave us room for two one-ofs to help smooth out our deck's edges, in case things fall apart for our primary plan.
Another potential issue is various hate cards. Graveyard hate shuts down our combo (although that will mostly be an issue for post-sideboard games, which we can hopefully fix with some sideboard cards), and cards like Thorn of Amethyst, Thalia, Guardian of Thraben, and Damping Sphere are also problematic since they tax our spells. Void Snare offers a nice, main-deckable catch-all to bounce whichever of our opponent's permanents is most problematic.
Mastermind's Acquisition is another card that helps us prepare for the worst-case scenario, which for Underworld Breach is that we mill our entire deck to try to mill our opponent out with Brain Freeze only to find that Brain Freeze isn't actually enough to win the game, either because our opponent has something like Emrakul, the Aeons Torn in their deck to keep shuffling their graveyard into their library or because our opponent is playing a deck with Veil of Summer, which fizzles Brain Freeze since it is blue. A singleton Mastermind's Acquisition lets us get another finisher from our sideboard. Grapeshot or Empty the Warrens both offer ways to win through Veil of Summer and Eldrazi. If we don't need a backup finisher, we can always snag a value card from our sideboard or just exile Mastermind's Acquisition to escape something from our graveyard. Burning Wish is another option in this slot, although since Underworld Breach allows us to repeatedly cast the same card from our graveyard and we have plenty of mana of any color thanks to Lion's Eye Diamond once we start comboing, Mastermind's Acquisition seems like it might just be better in the deck (although it's also possible that some long-time Legacy player will explain how this idea is super wrong and that Burning Wish is better).
All in all, this leaves us with a deck that can not only kill as early as Turn 1 but should also be able to find its combo pieces with some consistency and even has a decent backup plan if our opponent has a way of fizzling our primary Brain Freeze kill: Underworld Breach Combo!
Conclusion
While Legacy is the format where Underworld Breach seems most obviously broken, I wouldn't be surprised if someone figures out a way to make it do crazy things in Modern, Pioneer, and maybe even Standard as well! What do you think about Underworld Breach? Did I miss anything obvious that could improve the Legacy build? Do you have some ideas on how to make Underworld Breach broken in other formats? Let me know in the comments!
As always, leave your thoughts, ideas, opinions, and suggestions, and you can reach me on Twitter @SaffronOlive or at SaffronOlive@MTGGoldfish.com.
