I have no idea if my preview card will have any impact on Standard, Modern, or any other 60-card format. I will leave that to the vast, playtesting uni-mind that pores over every card in advance of the Opens, Grand Prix, and (of course) the Pro Tour to figure that out. I've been too busy musing about the ways I'll play the card in Commander, where it's destined to shine.
I'm going to guess you want to take a look at what I'm talking about before I start talking about the 99-card applications I've been finding for this newest member of several of my Commanders decks.
Let's take a quick look at what this card does, and then we can start looking through our stacks of Commander cards and seeing what decks it will fit into. It's pretty unique among clone effects in that it actually replaces the creature in play—bouncing it and putting a token copy of it into play. Very flavorful, and a little bit surprising that this flavor space for clones hasn't been explored before. Just on the basis of flavor, it's going right into my Lazav, Dimir Mastermind deck; which is built around a hard-boiled crime novels theme. The idea of removing the target from play and replacing it, albeit under your control, is straight out of any number of paperback original novels.
Supplant Form | Art by: Adam Paquette
At first blush, it seems like the best way to use this card is against your friend's annoying reanimator deck; the one plucking an Elesh Norn, Grand Cenobite or Jin-Gitaxias, Core Augur from their graveyard and putting it into play with a flashed back Unburial Rites. End of turn, you can just bounce their creature and get a copy of Jin-Gitaxias all your own that forces them to discard their hand. Don't worry about why all the other players are now looking at you through narrowed eyes. They don't have a hand to work with, and you are ripping through your deck, seven cards per turn.
It doesn't even need to be that dramatic. I love the idea of swinging the momentum of a game by bouncing a freshly-cast Consecrated Sphinx at the end of your opponent's turn, and untapping to build your hand up. And figure out a way to not let them resolve their Sphinx once the turn makes its way inexorably back to them, with you drawing at least two cards on each other players' turns. Really, any expensive card that your opponent has invested an entire turn in for a big game-swinging payoff…is going to be ripe for exploitation by this card; with you getting to take full advantage and untap and protect your token creature.
I am most looking forward to hijacking some Primordials with this thing. I have had some long, drawn-out games that have come down to Rashad Miller playing either a Diluvian Primordial or a Sepulchral Primordial. They gave him a huge advantage by casting a handful of spells, or reanimating a host of creatures. With Supplant Form in hand, you can wait until the Primordial resolves and targets in graveyards have been chosen. You then respond by playing our fun, new toy and making a copy of the Primordial. You can then hijack the cards he or she targeted in graveyards other than your own (with a bonus card coming from the original caster's yard). When their original Primordial attempts to resolve, and those targets are no longer there, those attempts will be countered. Your opponent will still get to resolve the one that was targeted in your yard, but you should have a 3-to-1 advantage in a four-person game. You had better do something pretty exciting with those cards and that token though, since your opponent will be untapping in a couple of turns with a Primordial in hand and a grudge to settle.
Of course, you can always use it on your own Primordials, assuming that is the type of gaudy card advantage you enjoy when you play Commander. It is not for everyone. Some people actually like keeping their friends. But if you are made of sturdier stuff than that, you can always play a Sepulchral Primordial, reanimate a handful of your opponents' best dead creatures. You can bounce your Primordial back to your hand, make a copy of it, and do a little more reanimation. You will still have the original Primordial in-hand…assuming your friends have somehow not shuffled up their cards and are starting a game without you in it.
You get to triple-up on any of your good "enters the battlefield" effects. Just flipping through my beloved Momir Vig, Simic Visionary deck; I see Acidic Slime, Solemn Simulacrum, Gilded Drake, Mystic Snake, Eternal Witness, and Draining Whelk as powerful sequences of cards to cast on either side of playing Supplant Form. Because it bounces the creature before it puts the token into place, it allows you to have fun with your legends, like Prime Speaker Zegana.
The card I am most excited about is Ixidron—a card that has threatened to end a couple of friendships at the Commander table—and getting to use its ability several times. I even end up with two essentially "face-up" copies of Ixidron at the end of the Supplant Form chain since Ixidron cannot turn token creatures face down.
There is no end to the forms you can supplant: from generating card advantage off your Nucklavee—you get to keep getting a red sorcery along with your Supplant Form—to bouncing the Commander your opponent has spent the last few turns building their way back up to…and attacking them with a copy of it; to whatever it is you enjoy doing when you play Commander…but doing it three times.
I already need three copies of this card for my existing Commander decks, and I can't imagine building a blue deck without one. Hopefully, I can start making some headway during Prerelease weekend.