It has been a while since a set has had the chance to impact Legacy and The EPIC Storm! Looking at all of the cards in Phyrexia: All Will be One, there are a few that should be tested in TES and a couple more combo all stars for other formats.
The Mycosynth Gardens
What appears to be a low-powered filter land just happens to generate an extra three mana with the best artifact in The EPIC Storm, [[Lion’s Eye Diamond]]. With the copy ability of [[The Mycosynth Gardens]], one can create a tapped copy of an artifact. Fortunately and crucially, for [[Lion’s Eye Diamond]], it does not have to tap to activate. At the cost of a land drop, [[The Mycosynth Gardens]] is a second copy of [[Lion’s Eye Diamond]]. This is the best use of the card, but if [[The Mycosynth Gardens]] is just dead when drawn without [[Lion’s Eye Diamond]], it would not be close to playable. There are two main edge cases to consider for the card. The weakest of these is to copy a [[Mishra’s Bauble]]. This converts a land drop into a new card two turns from activating [[The Mycosynth Gardens]]. This is not a Legacy powered interaction, but is possible in a pinch. Next, [[The Mycosynth Gardens]] could copy any artifact in play to provide another piece of Artifact to enable Metalcraft for [[Mox Opal]]. This is another way to immediatley provide colored mana. Tapping the land for mana will be better more often, but enabling [[Mox Opal]] is something to be aware of. Unfortunately, copying [[Wishclaw Talisman]] is not a good play. [[The Mycosynth Gardens]] will not have any Wish counters on it, meaning that it will not be able to tutor anything.
This card is likely borderline in The EPIC Storm. It may be better than a slot like the fourth [[Mox Opal]], but the manabase can not handle the extra stress from pseduo colorless lands. [[The Mycosynth Gardens]] is a niche roleplayer if it even is played at all in The EPIC Storm.
While The EPIC Storm will not be playing [[Minor Misstep]]. It is a card that opposing Blue decks will be testing for the next few weeks. Unfortunately for [[Minor Misstep]], counterspells that trade evenly or down on mana are not very playable in Legacy. Most counterspells that do see play do not cost mana. It is hard to compete with that type of efficiency. The other mana counters that do see play — [[Pyroblast]] and [[Hydroblast]] — are more flexible in many ways. This makes it hard to justify slots for [[Minor Misstep]] long term in most fair Blue decks. As for playing against this card, it has close to the same impact as a [[Spell Pierce]]. It can counter a piece of mana or sometimes a protection spell if one is not careful, but rarely delays a win by more than a turn or so. For the next few weeks, playing out [[Lion’s Eye Diamond]] early when the opponent does not have a blue mana up is the best way to beat a [[Minor Misstep]].
Exploring yet another format, Pioneer [[Lotus Field]] combo decks have been at the top of the format since its inception. One of the structural issues with the deck is that it is hard locked by a limit of turn three and needing two other lands. Playing [[Lotus Field]] before having the other lands is essentially conceding the game. However, [[Mirran Safehouse]] changes this. When a [[Lotus Field]] ends up in the graveyard by any means, [[Mirran Safehouse]] will have its ability to add three mana of any color, effectively making the [[Mirran Safehouse]] cost zero mana. Then, one can [[Hidden Strings]] it to their heart’s content to make all of the mana needed to win. While an artifact is much more vulnerable than a Hexproof Land, the speed and flexibility of the card leads to some additionaly equity. In the Modern version of the deck, where one gets to play actual [[Twiddle]], [[Mirran Safehouse]] opens up turn-two wins. By playing the [[Lotus Field]] on turn two and with the Enters the Battlefield Trigger on the stack, one can [[Twiddle]] the [[Lotus Field]], add three mana, sacrifice the [[Lotus Field]] to its own trigger and then play a [[Mirran Safehouse]] that taps for three mana!
A Complete Review
I am excited to play with these new cards! They promise to provide a couple weeks of testing, if not long term format shifts. If you are interested in the development of The EPIC Storm, Gruul Breach, or either of the [[Lotus Field]] decks, head over to the Storm Discord for all of those and almost every other format in Magic. If you think I missed a card from Phyrexia: All Will be One, let me know on Twitter!