With M15 spoiled in its entirety, I have analyzed each card and identified those most likely to see Standard sideboard play during the final months of this season and after Standard rotation this fall.

Editor's Note: Our Trader Tools plugin is still being updated with the current M15 info, so the card formatting will be adjusted once the update has completed.

Wall of Essence, a Stronghold reprint, was before my time playing Standard, but Wall of Hope used to see some sideboard play out of control decks as an answer to rush aggro decks. It does cost one more mana than Wall of Hope, but its increased toughness allows it to block bigger threats and gain more life. And it even survives burn like Lightning Strike, so it's more powerful overall.

In practice, this card will effectively shut down two small attackers for the price of one, and it's also capable of sitting in front of a huge attacker to gain a big chunk of life. Against creature decks full of 2/2s, this is technically an upgrade over Nyx-Fleece Ram, but it's a different story against pure Burn. It will be interesting to see if this "new" card is widely adopted.

Aetherspouts is comparable to Aetherize, but this new version returns the creatures to the library rather than hand, which generates card advantage and leaves the opponent unable to simply re-cast everything. It's very close to a one sided blue Wrath. It wouldn't be a stretch for Sphinx's Revelation control decks to sideboard this in where it would serve as an additional Wrath that fills the curve between Supreme Verdict and the increasingly popular Planar Cleansing.

Aetherspouts also seems really interesting from the sideboard of Blue Devotion against other creature opponents. It would be an absolute mirror-breaker against an unwitting opponent. It could have value in other matchups, too, like against aggressive green opponents playing Mistcutter Hydra.

Into the Void offers the potential for a significant tempo gain against creature opponents. It seems quite excellent in the Blue Devotion mirror match where it has the ability to deal with creatures, such as Thassa, God of the Sea, Master of Waves and the various flyers.

It also has value against midrange green opponents, where the 4-mana Into the Void is likely to generate tempo against their expensive creatures.

In Blue Devotion, I actually think this card has potential against Black Devotion as well. This matchup revolves around tempo, jockeying over board position and racing. I don't like the idea of Blue Devotion bringing in narrow answers like Negate against Black Devotion, but something like Into the Void is much more powerful, a much better topdeck, and it focuses on the fight that really matters. It's a clean answer to two copies of Pack Rat and huge tempo gain against any two of Desecration Demon, Nightveil Specter and Lifebane Zombie.

Continuing down the curve of powerful blue cards that disrupt creatures is Polymorphist's Jest. This card reminds me very much of Sudden Spoiling, which saw some Standard play and actually remains a playable Modern sideboard card. The new card is not quite as powerful, but very serviceable, and is a small boon for the color blue.

It's an ideal sideboard card against creature opponents, particularly large creatures or those that rely on synergy. It's a great way to deal with an otherwise difficult creature--say Thassa, God of the Sea or Stormbreath Dragon--by destroying it before it turns back to normal at end of turn. The card is great on defense, but also a fine offensive trick for shrinking blockers or paired with removal and repeatable damage effects.

In Standard, it would be excellent against both Blue Devotion and Jund Monsters decks and would seem to be solid against Black Devotion, where it could effectively counter the ability of Gray Merchant of Asphodel, and seems excellent against Pack Rat.

Again, it may be best out of the sideboard of a racing deck like Blue Devotion.

Stain the Mind is truly meant for the sideboard and is one of the most practical options available to black in M15.

This is a mono-black version of Slaugher Games. While I don't think it's necessary against the already favorable Sphinx's Revelation matchup, every bit counts and it would clearly be effective there. It's also available to black aggro decks and any other B/x deck that doesn't have access to red.

The fact that it can be countered is relevant, but not hugely so because the commonly accepted wisdom of the pros is to cut countermagic like Dissolve in the matchup.

This card may be more relevant after rotation depending on how the metagame develops, but based on the relatively slow nature of Theros block constructed, I expect this card to be excellent, particularly in the various planeswalker-based control matchups that arise.

The most important red sideboard card in the set is a reprint, and it means Chandra, Pyromaster will be in Standard for another year.

This card serves two purposes: first, as an engine for destroying opposing x/1 creatures and turning off blockers; and second, as a card-advantage draw engine in attrition matchups. This makes it a great sideboard card and something to keep in mind for any red deck going forward.

Back to Nature is a huge blowout for enchantment decks. The enchantment theme has been pushed really hard for the last year, but times might be a changin'.

This card completely wrecks enchantment decks, which all seek to flood the board and rely on synergies. At two mana, and with instant speed, this card will always remain a bogeyman, and as sideboard hate, it will exist to prevent enchantment strategies from becoming too dominant for long.

Naturalize is a great addition to Standard and a new tool in green's arsenal. While there are other options, none are as simple, efficient, versatile and splash-able as Naturalize.

Stealing some thunder from Naturalize is Reclamation Sage, which is a sorcery-speed Naturalize with a body for an additional colorless mana. This card is the new gold-standard in Magic for this sort of creature, and, as an Elf, it will take over sideboard slots in Legacy Combo Elves.

This card is great in Standard, perhaps maindeck playable, and will be the first option I'll turn to for this effect in the future of my Standard green decks.

As a one mana artifact, Profane Memento has all the makings of an excellent sideboard option. While it's not great graveyard hate, it might have some value against the Standard G/B graveyard-filling Dredge deck if it grows in popularity.

With the same logic as the last card, Tormod's Crypt is a great sideboard card and is something to keep in mind if graveyard decks ever take off in popularity.

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So what cards from M15 do you think are going to have a big sideboard impact in Standard?

-Adam