I know why you're here. It's okay. You can watch TCGplayer's two minute preview video, or scroll down a little further to see the card directly.
I promise you won't be as excited as me though.
This awesome Soldier is one of the most powerful Humans ever printed and has had one of the biggest impacts across all constructed formats since her first printing in Dark Ascension in February of 2012. She continues to be a format staple in Legacy, Modern and even Vintage! Few cards, let alone a small white creature, can boast such an impressive reésumé. If you don't yet have your playset, I have good news: She is returning in Masters 25!
Today I'm going to share some of the top lists across all three formats and discuss the role Thalia, Guardian of Thraben plays in each.
Let's start with her current home in Vintage:
This is the most creature-centric deck in Vintage, rocking only Null Rod and Thorn of Amethyst as the lone non-creature, non-mana cards in the deck. The idea of the deck is to pressure the opponent while disrupting their ability to cast their spells. Thalia, Guardian of Thraben makes all their spells cost one more, which includes every Mox or Black Lotus they want to play. Wasteland and Strip Mine do further work to keep them off sufficient mana to do what they want. Thalia's effect is symmetrical, but this deck is built such that it casts all its non-creature spells on the first turn of the game, just before casting Thalia, and thus never has to pay extra while opponents have to pay extra for nearly everything. Vintage is a creature-light format, so Thalia does a lot of work against most decks. She is even joined by her three mana counterpart Thalia, Heretic Cathar.
If powering out Thalia with Black Lotus and Mox Pearl isn't quite your thing, that's ok because she is every bit as good in Legacy as she is in Vintage—if not better!
I don't usually play Legacy, but when I do, I play Death and Taxes. Fortunately for me, it's been a good deck for years.
The goal of Legacy Death and Taxes is to keep your opponent from being able to cast their spells just long enough to attack them to death with little white creatures. What could possibly be a more Craig Wescoe strategy?
Like the Vintage deck, Legacy Death and Taxes looks to use cheap artifacts to power out creatures. Unlike Vintage, however, you don't have access to Mox Pearl, Black Lotus, Sol Ring and other restricted accelerants. Instead you have Aether Vial. This actually works to our advantage because it means the opponents likewise don't have access to the Power Artifact mana of Vintage. This makes it much easier to keep them from being able to cast their spells.
The deck uses Wasteland and Rishadan Port to keep the opponent from having access to their lands while Thalia, Guardian of Thraben makes all their spells cost one more mana. This means they're unlikely to resolve a spell that costs more than one or two mana per turn, if even that. While Aether Vial ticks up and allows us to deploy all our creatures on curve, we are free to spend our mana tapping down opposing lands on their upkeep with Rishadan Port, or destroying their dual lands with Wasteland. If the opponent plays a creature we need to get rid of we have Swords to Plowshares as the most efficient creature removal spell ever printed.
We also have Mother of Runes to protect Thalia so that even a Lightning Bolt or opposing Swords to Plowshares cannot get the opponent out from underneath Thalia's tax on their spells.
There is another deck in Legacy that uses Thalia to great effect.
The strategy in Maverick is similar to that of Death and Taxes, except instead of using Aether Vial to power out Thalia it uses Deathrite Shaman to do so. And instead of using Rishadan Port to assist Wasteland in keeping the opponent's lands in check, it looks to search out Knight of the Reliquary as soon as possible and start finding Wastelands to kill all the opponent's lands. It can then use Green Sun's Zenith to find Ramunap Excavator to replay Wasteland each turn to completely lock the opponent out of nonbasic lands. Scryb Ranger can also do some work by untapping Knight of the Reliquary to find another Wasteland in the same turn.
Both decks are centrally concerned with mana denial, a strategy that plays right into the strengths of Thalia. It's really difficult to get out from underneath a Thalia lock when your Brainstorms cost two mana instead of one.
While Thalia is an all-star in both Legacy and Vintage, she is also exceptionally good in Modern.
Mana denial is often the strategy that goes hand-in-hand with Thalia, but in Modern she is strong enough on her own that she goes into decks that have no other mana denial cards in the entire strategy. For instance, Humans decks takes advantage of the first of her two tribal affiliations.
Being a Human, Thalia pumps Champion of the Parish and is pumped by her trusty Thalia's Lieutenant. The deck runs Aether Vial as its only spell, so Thalia's tax mostly affects your opponents' spells. This disruptive ability is key against several top strategies in Modern. Against Burn it gives the deck enough time to deploy its threats before the Burn player is able to resolve enough burn. Against control decks she buys one more turn before Supreme Verdict or Anger of the Gods would be able to resolve. Against combo decks such as Storm or Ad Nauseam they have great difficulty resolving all their combo pieces in succession when each spell is taxed by Thalia.
Unlike in Legacy, you don't have Mother of Runes to protect Thalia from removal, but in this deck there is Kitesail Freebooter and Meddling Mage to help keep Thalia safe.
Another deck, one that more closely resembles Legacy Death and Taxes is Green-White Hatebears.
This deck uses Leonin Arbiter as Thalia's partner in crime for keeping the opponent from being able to cast their spells. In a format like Modern, with mana bases largely reliant on fetch lands, Leonin Arbiter's double tax slows the opponent down considerably. This makes Thalia's tax that much more oppressive to an opponent trying to cast their spells. We don't have Wasteland or Strip Mine, but with Leonin Arbiter on the battlefield, Ghost Quarter can turn into Strip Mine. It also has some tricks with Aether Vial such as putting Flickerwisp onto the battlefield on your own end step in order to blink out an opponent's land until their next end step. The same trick can be done on their upkeep or by blinking Flickerwisp with Restoration Angel.
Another variant of Aether Vial based land denial is Black-White Eldrazi Taxes, which combines the acceleration of Eldrazi Temple with the land denial combination of Ghost Quarter and Leonin Arbiter.
Much like the Green-White version, Thalia and the Cat Cleric work in tandem to keep the opponent from being able to cast their spells, all while Aether Vial ticks up and allows us to deploy all our threats on time, including Thalia. Like the Vintage Eldrazi deck, this one also pairs Thalia, Guardian of Thraben with her three mana counterpart, Thalia Heretic Cathar for further disruption of the opponent's mana.
As long as players are casting plenty of non-creature spells, there will be a use for Thalia. Whether part of a mana denial strategy, a tribal strategy, or sometimes just a creature-centric tempo strategy, Thalia is quite often the best creature for the job. Despite being legendary, decks that play her often play the full four copies simply because she is so good at what she does. The next best option is Thorn of Amethyst or Vryn Wingmare, each of which is considerably less efficient of a card than Thalia.
Did I mention she can also be a commander for Commander too?
If you don't already have your play set of Thalias, Masters 25 affords you a perfect opportunity to acquire it. There are few cards in Magic that are staples across every non-rotating Constructed format, but Thalia, Guardian of Thraben is definitely one of them.