It's no surprise that Theros Limited offers a lot of depth in Booster Draft with its wide variety of viable color combinations. Whether it's black or green devotion, aggressive heroic strategies, or other aggressive offerings, Theros has proven itself to be a diverse Limited format for players to explore.
And while Sealed being a very different beast than Booster Draft, the same applies for players registering and building from six booster packs as well.
The first aspect of Sealed that is different from Booster Draft is the desire to play with more lands. While you may see lands shaved from hyper aggressive archetypes in Booster Draft, you'll rarely see a player who is doing well in Theros Sealed with less than 18 lands in their deck. More lands ensures you can properly play all of your biggest and most powerful spells, but more importantly, lands let you get monstrous.
One aspect of Theros Sealed that has not changed over time has been the value of creatures with monstrosity. You may be shocked to learn this, but monstrous creatures are big. Very big. However, one of the downfalls of putting too much effort into growing one monstrous creature in Booster Draft is the threat of a Voyage's End or Griptide ruining your day. While this can happen in Sealed as well, the decks that are often including copies of the powerful blue disruption typically aren't backed up with an aggressive heroic strategy, which is what often made a timely Voyage's End lethal if you were reliant on a Nessian Asp to dominate the battlefield.
Another key value of monstrosity is that you don't need to make a creature monstrous in order to make your opponent play differently. Due to the threat of being destroyed by a creature that can jump in size, players facing down a monstrous creature in its "tame" form will have to make plays expecting that the opponent will make that creature monstrous. This means making unfavorable blocks as well, and oftentimes players must do this against the threat of monstrous creatures
In Sealed Pack, the inconsistency of nabbing a synergistic and coherent heroic deck that is capable of fast wins is less, which means there are fewer ways to keep a giant creature in check. This makes Nessian Asp, which was already very good in Booster Draft, into one of the Sealed Pack format's defining creatures.
However, you're not limited to green. According to No. 17 Ranked Player Paul Rietzl, each color has some monstrous creatures that are worth considering. "I think that in the Sealed Deck format, if you just look at all of the monstrous creatures from common to mythic, their monstrosity costs are very undercosted given the speed of the format," he said. "You very frequently have time to monstrous them and they have a very big impact on the game. In the Sealed format, an unanswered Nessian Asp ends a lot of games. Even the answers that are more temporary like Voyage's End are often just stalling the inevitable."
Aside from the power of monstrosity, Rietzl's research also revealed to him which color is the best one to consider when building a Sealed deck. Since Theros has been released, there have been three Grand Prix events that have featured Theros Sealed (excluding Team Sealed). Rietzl compiled the undefeated decks from these events into a spreadsheet, and after analyzing each deck, it became clear that black was the color that stood above the rest.
"Anything I can have in a deck that can deal with a creature once it's gone monstrous is key. This is why Sip of Hemlock is so good in Sealed Deck, but only mediocre in draft," he said, emphasizing the power level of black and the frequency in which black has shown up in the undefeated decks from previous Theros Sealed Grand Prix events. Booster Draft all-stars such as Disciple of Phenax and Gray Merchant of Asphodel are obviously quite good when supported by more black cards, but other options which were good but not great in Booster Draft become stellar in Sealed.
One of these cards is Sip of Hemlock, a card that was certainly powerful in draft formats by providing players with hard removal in a format that lacks ways to directly deal with creatures. Its power level becomes much more pivotal in Sealed, as it is a surefire way to deal with a monstrosity creature no matter the situation.
Another card that changes drastically in playability is Lash of the Whip. While Lash offers a form of removal, its inability to take out a heroic creature that has already tripled in size was one of its downfalls and a reason why the card is not as high on the list of key black cards as it may have been in other Limited formats. In Sealed, removal is king, and Lash of the Whip oftentimes answers exactly what you need to take out.
Cavern Lampad, another creature that varies widely from Sealed to Booster Draft, is also on Rietzl's list of powerful options in black. In Sealed Pack, bestowing the Lampad onto an already large creature is a good way to quickly end games, and given the slower nature of Sealed, this is a quick route to victory when it goes unanswered.
Black also has the benefit of being a fine pairing with blue, especially when you open solid cards such as Returned Phalanx. Being able to have access to any copies of Voyage's End, Griptide, and Sea God's Revenge that you open is a nice perk as well, since all three cards remain very powerful in Sealed Pack.
We'll see at the end of the day if the undefeated decks from Theros Sealed continue to follow the trends Rietzl has studied, or if something unusual will show up in the spotless decks after nine rounds of competition.