Possibility of a Planar Reprint:  3
It’s Pacifism with a mostly irrelevant tribe tacked on. If the Tribal supertype wasn’t pretty much dead in the water, I’d actually rate this pretty high.
Possible Plane(s): Mercadia: 4
So it’s a Rebel aura, Rebels are tied to Mercadia. That’s pretty loose though, but there are no hints in the art or flavor text so Mercadia is the best guess we’ve got.

Centaur Omenreader 

Possibility of a Planar Reprint: 5
Centaur Omenreader is interesting, personally, I like it but there are two reasons I don’t think we’ll see it anytime soon. First, it’s a snow creature. That’s not super bad, we just went to Kaldheim, but as a snow creature it’ll probably have to be printed in a snow set and I’m not sure how soon we’ll get one of those again. Second, the ability is pretty out there. It’s not broken, but it’s a type of design we don’t really see anymore.
Possible Plane(s): Kaldheim: 6
Given the name Omenreader and its snow supertype, my best guess would be the omen and snow heavy plane, Kaldheim. Theoretically Dominaria is also possible, but I definitely get more Kaldheim energy from the Omenreader title.

Emblem of the Warmind 

Possibility of a Planar Reprint: 4
While Emblem of the Warmind is a pretty fair and balanced card, it’s also pretty far off from what an aura is really supposed to do. It’s a bit confusing that just having one creature enchanted with this card gives ALL your creatures haste. For entrenched players, this card is a side note, but for new players this could cause some real bad moments. I don’t see it ever getting printed outside of some weird commander precon perhaps.
Possible Plane(s): ???
As for what plane this comes from, that’s hard to tell. The art is generic fantasy and doesn’t give any real hints. The flavor text reads similarly with no real indications. Thus the only real guess I can make is Dominaria, but even then I’m not confident enough to score it.

Imperiosaur 

Possibility of a Planar Reprint: 6
Decent stats, balanced creature, hell yeah! I think if we ever go to Muraganda, we’ll definitely be seeing this card. Thing is, I kind of doubt we ever will.
Possible Plane(s): Muraganda: 10
Flavor text confirms this card is from Muraganda so we have a solid confirmation here!

Phosphorescent Feast 

Possibility of a Planar Reprint: 3
Chroma was the precursor to Devotion and a mechanic we’ve seen Wizards' staff not be super hot on. Now you might, rightfully, point out that the original printing did not have Chroma, but if you look at the Oracle text, it has been errata'd to now have Chroma. Even without it, this card is painfully mid, and thus I seriously doubt we’ll ever see it again.
Possible Plane(s): Lorwyn: 10 
We actually did see this card get a planar print on Lorwyn, although interestingly the flavor was changed from a pixie vibe to goblins gorging themselves. I think both arts and flavors fit Lorwyn though.

Mistmeadow Skulk 

Possibility of a Planar Reprint: 5
Mistmeadow Skulk is a decent card, but it suffers from having Protection, a keyword Wizards doesn’t really use anymore. I think if we ever see Protection return we might see this card again, but even then the plane it hails from holds it back.
Possible Plane(s):  Lorwyn: 10
So not only did we see Mistmeadow Skulk printed on Lorwyn, but Mistmeadow is a location on Lorwyn thus thoroughly tying it to the plane. Unlike other cards with more generic names, we’re unlikely to see this card outside of Lorwyn in the future.

Skizzik Surger 

Possibility of a Planar Reprint: 3
Damn we’re kind of an outdated mechanic. Skizzik Surger has Echo, a mechanic hated by players and Wizards alike. Echo really shouldn’t return, and even if it does Skizzik Surger is not the kind of card that should return with it.
Possible Plane(s): Dominaria: 10
All the way back in Invasion we saw a card named Skizzik printed, and we saw it get reprinted in Dominaria. These are the only Skizziks we know of, and therefore Skizzik Surger is definitely a Dominarian creature.

Spellwild Ouphe 

Possibility of a Planar Reprint: 6
I’m biased because I love Spellwild Ouphe. I really want it to see a reprint because it’s such a cool ability on a card with some incredible artwork. The only issue is there’s no reason this would see a reprint anytime soon since it really doesn’t seem like something players are asking for. I have hope, but I can’t really give it any higher than a six.
Possible Plane(s): Eldraine: 2 Dominaria: 5 Lorwyn: 5 
So we’ve seen Ouphes all over the multiverse actually on Eldraine, Mirrodin, Dominaria, and Lorwyn. We know from the flavor text (and context of it being a reprint) on Brown Ouphe that the Mirrodin Ouphes are not native, and even if they were Mirrodin wouldn’t have something called “Spellwild”. The name definitely sounds like Eldraine, but the only Ouphe we see there is Oko’s, and it looks totally different so I’m not sure there. Dominara and Lorwyn could both have whatever  Spellwild is, but the Ouphes there also look entirely different, so we don’t have anything definite here.

Zoetic Cavern 

Possibility of a Planar Reprint: 7
Zoetic Cavern used to be playable y’know, and for my money I’d love to see it come back. I think if we ever see Morph again, we’ll probably see Zoetic Cavern in the set as an uncommon for draft or something. I look forward to your return, my Zoetic friend.
Possible Plane(s): Dominaria: 5 Rath: 4 Zendikar: 3 
So Zoetic literally means “living”...which doesn’t help us much. We know Tarkir has Morph, but this cave doesn’t really feel Tarkir so we can rule that out. We also know Dominaria and Rath have Morph, but there’s still nothing really tying it to either place. However…I have a crack theory. This card looks kind of like one of the Eldrazi Wastes from Zendikar, what if the cavern is Zendikar, a plane we know is alive, slowly retaking a destroyed area? It’s possible...right?

Witch's Mist 

Possibility of a Planar Reprint: 3
Why does the enchantment tap? WHY DOES THE ENCHANTMENT TAP???? Yeah…I don’t think we’re gonna be seeing this anytime soon.
Possible Plane(s): Dominaria: 2
I mean we have nothing to go on here but the robes she wears kind of remind me of a Samite cleric…and idk maybe the Overmother is a remnant of some cabal magic? Idk, honestly this whole card just hurts me. I love breaking barriers, but why does the enchantment tap?

Boldwyr Intimidator 

Possibility of a Planar Reprint: 5
We actually saw some Coward/Warrior interaction in the recent Zendikar set, so I think if we ever go back to Lorwyn, we’ll probably see this guy again!
Possible Plane(s): Lorwyn: 10
Similar to Mistmeadow Skulk, this card was printed on Lorwyn and is tied to the plane by name.

Goldmeadow Lookout 

Possibility of a Planar Reprint: 3
We don’t really see Spellshaper type abilities these days, and even if we ever do again I doubt this card is going to be among them. Tokens of pre-existing cards are slowly becoming more of a thing, but I don’t think anyone’s clamoring for Goldmeadow Harrier tokens.
Possible Plane(s): Lorwyn: 10
Same as Mistmeadow Skulk and Boldwyr Intimidator.

Bloodshot Trainee 

Possibility of a Planar Reprint: 5
Bloodshot Trainee is kind of an underwhelming card since it’s just a 2/3 for four unless you pump it, but maybe in a set with auras/equipment or focused around Ferocious I could see this making a return.
Possible Plane(s): Mirrodin: 10
Bloodshot Trainee was reprinted in Scars of Mirrodin, but the original art very clearly doesn’t show Mirrodin goblins or setting. For now the best tie we have is Mirrodin, but we could definitely see this guy on another plane at some point.

Edge of Autumn 

Possibility of a Planar Reprint: 4
I love Edge of Autumn, I just wish there was a format where it could truly shine. I think that it’s in that weird power range where it’s good, but too weak by today’s standards. It’s a catch up card in a color that’s always ahead. I could see this being reprinted at some point, but I think design philosophy would have to shift for that to happen.
Possible Plane(s): Pyrulea:4 Lorwyn: 3
Given the forest whimsy of the card, I could see this on Lorwyn, but since the focus character is standing on a massive leaf I’m drawn more towards the towering plane of Pyrulea (See Horizon Canopy)

Lumithread Field

Possibility of a Planar Reprint: 6
Okay so Lumithread Field is one of my favorite futureshifted cards. The art, the flavor text, the whole damn card just comes together to create a window into a world I want to see so badly!  It’s too bad that this card is just…medium. It’s one of the cards where the effect, although cool, isn’t something that really excites people enough for it to see print. A toughness buff is sweet, and the morph line is good for limited, but overall it’s just so tepid.
Possible Plane(s): Mirrodin: 4 Alara: 4
So my thoughts on this are muddled a bit. In all likelihood this shows us a new plane we’ve never seen before, but there are two very real possibilities for preexisting planes. The line “Bastion of the Suns” in the flavor text reminds me of Mirrodin, as does the vague techno theme of the art, but beyond that we’ve got no real ties there. The creatures depicted seem almost Esper in nature though, similar to the style of the Homunculi we see on Court Homunculus and on the Homunculus token. Plus to me, Morph would work pretty well for an Alara set given it would help bypass the three color cost of many cards (Similar to how it did on Tarkir).

Patrician's Scorn 

Possibility of a Planar Reprint: 7
I’m surprised this card doesn’t see more EDH play. It’s a really solid bit of white removal, theoretically wiping all enchantments for free at instant speed! It’s powerful, but balanced and a real contender to be seen again!
Possible Plane(s): Fiora: 5 Innistrad: 5
The flavor of the card itself doesn’t point in any obvious directions, but the vague sort of bougie vibe of the art and flavor text would land it right at home on Fiora. The other more ghostly flavor fits Innistrad perfectly, especially now that we’ve actually seen some enchantment support on the plane.

Sporoloth Ancient 

Possibility of a Planar Reprint: 7
It’s a pretty powerful fungus and people love them some fungus! I don’t think it’s likely we’ll ever truly see a return to the “spore counter” type of Fungi, but if we ever do then I truly believe we’ll see this guy get his day in the sun.
Possible Plane(s): Dominaria: 8
We’ve only ever seen this type of “spore counter” fungi on Dominaria, so to me that means it’s most likely where Sporoloth Ancient hails from.

Thornweald Archer 

Possibility of a Planar Reprint: 7
It’s a piker with Deathtouch and Reach with a relevant tribal typing, we’ll definitely see this guy at some point.
Possible Plane(s): Lorwyn: 2 Dominaria: 2 Eldraine:2
The art gives Dominaria vibes, but I can’t confidently say that. I’m basically just throwing in Eldraine and Lorwyn since both would also fit the flavor, but really this guy could go in pretty much any set with Elves.

Grinning Ignus 

Possibility of a Planar Reprint: 5
Grinning Ignus goes infinite with Birgi, and that’s about it outside of limited. In a draft environment it’s decent, it’s ability can soft ramp you and help it avoid removal. Grinning Ignus is the kind of card that’s just waiting to be abused. We’ll probably never see this guy again outside of Masters sets.
Possible Plane(s): Strixhaven:10
Grinning Ignus was printed in Strixhaven! Which is why I’m a bit surprised we haven’t seen a combo deck with it in standard rn. Someone get on that.

Ghostfire 

Possibility of a Planar Reprint: 3
I love Ghostfire. I’m an avid player of Canadian Highlander and this is one of my favorite secret techs in my Mono-Red burn deck. It may seem like a bad card, three mana for three damage is not a great rate, but the fact that it’s colorless means it gets around a lot of the traditional counterplay to burn strategies. Auriok Champion, Burrenton Forge-Tender, Kor Firewalker, Paladin En-Vec, Sanctifier En-Vec, Fiendslayer Paladin, etc. All of these cards totally fold to Ghostfire (And it’s sibling card Reality Hemorrhage). All of that said though, Ghostfire being colorless is also why it won’t get reprinted. To me that ability is too out there, plus having colorless spells without devoid would likely be a hassle. Sorry Ghostfire, but you’re benched.
Possible Plane(s): Tarkir: 8
I mean it’s a direct reference to Ugin, plus we saw Ghostfire Blade on Tarkir. I’m pretty sure this thing is from Tarkir.

Flowstone Embrace

Possibility of a Planar Reprint: 4
Oh good…another enchantment that taps. I like this card, but in most cases it’s a weird immolation and the effect is pretty out there so I doubt we’ll see Flowstone Embrace again.
Possible Plane(s): Rath: 7 Dominaria :7
Flowstone is something we’ve seen before, but only ever on Rath and Dominaria, thus it’s likely this card hails from one of those two places.

Nessian Courser 

Possibility of a Planar Reprint: 8
It’s a flavorful vanilla 3/3. I’m pretty sure we’ll see this guy in some future Theros set.
Possible Plane(s): Theros: 10
The Nessian Wilds is a location on Theros, plus this card actually saw print in the original Theros set. It’s from Theros.

Sarcomite Myr 

Possibility of a Planar Reprint: 8
Sarcomite Myr is deceptively good in draft, plus it’s just overall a decent card with great art. I hope we’ll see this guy soon.
Possible Plane(s): New Phyrexia: 9
It’s a Myr, it’s grotesque, and the flavor text references Brudiclad (A myr we know is from Mirrodin). This guy is definitely from New Phyrexia, but he might’ve gone to another plane so I can’t fully endorse that with a 10.

Blind Phantasm 

Possibility of a Planar Reprint: 8
Strictly worse Nessian Courser.
Possible Plane(s): ???
We’ve got no clues here. The art isn’t exactly distinctive (Despite being awesome). Sorry, but this one’s a big mystery.

Blade of the Sixth Pride 

Possibility of a Planar Reprint: 8
Another in the set of full art vanilla creatures. This one being very aggressive as a two mana 3/1. Also interesting but we saw this referenced on Imposter of the Sixth Pride in Modern Horizons.
Possible Plane(s): ???
I mean it’s probably Dominaria, but it could be anything.

Fomori Nomad 

Possibility of a Planar Reprint: 6
Another of the vanilla squad, but this is interesting as it’s reprint score is low due to it’s high planar score.
Possible Plane(s): Ir: 10
The Fomori are a tribe of giants from the plane of Ir, which is basically a mana charged plane that is said to be often visited by planeswalkers. We’re unlikely to ever visit Ir, but if we do then maybe we’ll see our friend there.

And that's it for Part III! After the next article, we'll be back to our regular, non-timeshifted content.
I'd love to hear what planes you think these cards might be from in the comments below! 
You can find me on Twitter @East2Westmtg or email me at East2westmtg@gmail.com.
As always I’ve been East2West, your resident full art vanilla planeswalker and tapper of enchantments, and I’ll see you guys on the battlefield!