Huh. For whatever reason, this would feel a lot better in or .

Actually, Neither of these is usual in red these days. Frostburn Weird is an exception because it calls back to the flowstone mechanic, but nowadays they are usually blue things (Water Servant, Watercourser, Metropolis Sprite, Aetherling). This could theoretically be a card, but as a Dauntless enabler, I like the subtilityof making it better.

First, white has never had either of these abilities.
Second, red still does get the +1/-1. there are two such cards in RTR block and an Aura in Avacyn Restored.
Third, the first ability appears only on blue and green. (and Torchling, which was a throwback though.)

Would you mind linking to the cards so we don't have to look them up?
The first ability is much more like to be "shieldbreathing," +0/+1, as seen on Windreaver.

amuseum, I've already stated that Frostburn Weird only gets this ability as a historical throwback to the Flowstone ability. The last red card to be printed with it outside Planar Chaos (which gave us Torchling and Flowstone Channeler) was Undead Leotau (and before that? original Ravnica's Viashino Slasher), so it's clearly not seen as a very strong part of Red's pie anymore. One-off +1/-1s I'm entirely fine with in Red (as found in Guise of Fire), but they make poor comparison for a firebreathing ability.

L2 accurately notes that the first ability is an adaptation of shieldbreathing (most recently seen on Foundry Champion and Wall of Faith). I'm putting in in my ideas file strictly to ahe a way to lower a creature's power in a dauntless deck, and I normally would not be suggesting this in an average block.

You give off very weird reasons to support this in white, which is the last place any of these abilities would appear.

1. Your set is supposedly influenced by Ravnica guilds. In both Ravnica blocks, red has had at least one such card with +1/-1 ability. Regardless of whether it appears again elsewhere. At least on Ravnica (or another such guild-based set), it seems sufficiently supported in red.

2. In fact, these abilities doesn't appear that often, period. (most likely because it's seen as a downside ability.) Whether it's blue or green or red, it has always been an extremely rare ability. So that's not really a reason to claim that it's not part of red's pie anymore. Nevertheless, it's a fact that every once in a while, we'll see a red card with one of these abilities (probably the latter ability).

3. Neither of these abilities are white. Ever. "Shieldbreathing" has been around forever, yet there is not a single instance of -1/+1 in white.

4. You say it's not a normal set. But it's based on Ravnica, and on Ravnica, these abilities are squarely Izzet. Not Boros nor Azorius.

5. Torchling has been reprinted in a Duel Deck, so obviously they feel comfortable with these abilities in red. Even green has a variant of Morphling. But not surprisingly, neither white nor black has a spin-off thereof. (I wouldn't hold my breath.)

[re: 5.] I would. I mean, really, why wouldn't they just keep going and make a black and a white morphling? It makes sense to me...

The rest of this, though... I don't want to get too deep into this, mind you... but while I agree with amuseum that -1/+1 isn't really white, I feel like that ability should go somewhere besides defaulting to blue cards that also happen to mention +1/-1. Seems a shame that we can't find a decent home for it. But, personally, I was never a fan for shoving it in white, since white already got +0/+1. Why would it also get the (usually) worse version?

I don't know. If it was up to me, and I worked at Wizards, I'd probably start pushing -1/+1 on a bunch of artifact creatures, since it doesn't seem to belong to any of the colors.

1/2: I would hardly call the slasher a card that demands a callback, and certainly a single card in two sets is hardly a regular thing when one only exists because they were grasping for straws for U/R abilities.

3: One could argue it's barely settled in any color at all on account of being exceedingly rare (and until they decided to make it blue, it was green). There are less cards with that ability in the history of the game then hexproof cards in RTR block. Putting it on this one white card because the set needs it (which isn't proved. The set is just a collection of random idea) is hardly a stretch.

4: "These abilities" are not "izzet". They are blue in the current pie. Weirds are Izzet. Instant/sorcery shenanigans are izzet. +1/-1 isn't izzet. Especially not when it "squarely was" Rakdos in original ravnica block (Carrion Howler, Riot Spikes, Unliving Psychopath, Viashino Slasher)

5: Your point is? So were Sunlance and Harmonize. That doesn't make those cards are in-color for current white or green.

Re 1) and 4): The Suvnica project is only "based" on Ravnica to the extent that it's a reimagining of what Ravnica might be like if it were completely different. Even if -1/+1 were "Izzet", that certainly doesn't mean it would be Tezzi, because the whole point in Suvnica is reimagining each of the ten guilds with the colour-based "ends" and "means" swapped over. From the original introduction to Suvnica in April 2013:

> What we will be doing is creating cards, cycles, and mechanics for guilds that have entirely different creative identities that the ones we've been thinking about for the last eight years.

FWIW, I liked the use of -1/+1, unusual but not out of place, as a dauntless enabler.

Re 5): Blue is the primary shapeshifter colour; I wouldn't say green is any more shapeshifter-y than white or black. I'd expect both a black and white Morphling variant in the fullness of time.

re 1/2: nobody said it was regular thing for red. i said every once in a while they would make a red card with this ability and they won't shy away from doing this if the card calls for it. that's why slasher and frostburn are perfectly acceptable as red. In short it's very comfortable as red.

re 4) Power switching is in both red and blue, and this is a variation of that.

Well if we're gonna reimagine the guilds, this might as well be W/B. black sacrifices body for power, and white sacrifices might for protection.

For that matter, this isn't blue at all because blue is the least concerned about physical attributes. It could retain the ability to switch power and toughness with each other (because blue is still about trickery), but it shouldn't do so incrementally. So Aquamoeba is blue, but Water Servant is not.

Switching P/T is also black, which is inline with what I said above. So altogether, these abilities will be assigned like so.
-1/+1: mainly white and green
+1/-1: mainly black and red, sometimes white
switch P/T: mainly blue and black, sometimes green

R&D is on official record saying that +1/-1 and -1/+1 is now a blue thing, as a reflection of blue's shapeshifting abilities. And we have had had multiple recent cards to prove it (as I demonstrated in my very first answer in this thread)

"switch P/T" (as in Aquamoeba and Inside Out) is still U/R, I'm fine with that.

+X/-X in any form, however, is clearly no longer black. The last mono black cards were in Lorwyn (Nameless Inversion, Thorntooth Witch) and all the more recent ones were multicolored (Auger Spree, Sangrite Backlash, Warped Physique)

We are reimagining Ravnica's flavors and and building new guild identities based on those. Not reimagining the color wheel. this is not planar chaos!

To put in my two cents, I think that -1/+1 is a fine fit for white. It evokes whites occasionally pacific nature, in a way. I'd certainly be more okay with it that other "stretches" of the color pie, like life gain in red or vigilance in blue. I don't think it's really a stretch at all, just something that hasn't yet been done.