I've been around the block, so to speak, and at least some of the posters on these boards know I've got a decent bit of historical perspective ragarding MtG, and some of the stuff I say makes it's way into discussions and articles in other places. So I'd like to use the opportunity to plant an idea in hopes it makes it to more influential folks with more ears to bend.
I've a feeling it's about that time that MtG needs a bit more color pie exploration. This stuff happens every so often, effects get shuffled around. Sometimes it makes sense flavor wise so it's easy to justify it to folks who don't get design necessities, sometimes it's far less subtle and just needs to be done. Happened with a lot of mechanics, really, and it's rather a good thing that it does happen.
So here's two suggestions that would likely impact Pauper, can be justified flavor wise and are in line with previous such effect shuffles and expansions:
Idea 1: Give green limited reanimation. Green's been a getting variety of Raise Dead effects lately ("lately" from the perspective of an Eldrazi) but what it could use is an Unearth. Sure, Unearth itself is one of those what-were-they-smoking crazy strong commons from Saga block, so the green variant would obviously have to be less powerful. For example it could return only a 2cc dude for one G, or even only a mono-green 2cc dude for one G.
Flavor and color pie wise, Black and Green fiddle with the graveyard anyway, and regrowing / revitalizing things is very easy to immagine in green. You could justify the limited scope and power of such an effect in green because green can easily replace/patch together a small thing, while it couldn't reanimate something huge because getting huge takes growth and all that good green philosophy stuff. Seedlings are dime a dozen, ancient oaks are gone when they topple, I could come up with flavor texts for such green cards for days. It could also make for a nice thing to associate with Dryads to flesh them out (not as a tribe necessarily, but as a motiff).
Mechanically there's room for several iterations - you can make a weak one cost 2 mana, you could make one of them create a token that's a copy of something small in your yard, whathave you. And the reason for this is that this specific effect would help green keep specific threats / roleplayers on board somewhat through heavy removal, and it would help stompy, and it would certainly help madness decks get Mongrel back after it instantly eats removal. Unearth has the ability to make something cost you more when you cast it then it costs to reanimate it, which helps combat enemy card advantage through redundancy. It'd be strong, sure, but if splashing was easier in Pauper a lot of green decks would be running Unearth for sure and likely will be running it if they ever give us a better common mana base, so actually giving green an Unearth or two might not be a bad idea at all.
It's a powerful effect, to be sure, and there's plenty of silly strong things that could be done and become routine with even a less powerful green unearth but I believe it'd be quite worth it.
Idea 2: Give Black a Rampant Growth, but one which can only fetch basic swamps. Black is already running 2-mana card draw wherever it can, mostly to dig for lands, and it's spells and threats are significantly more expensive than anyone else's threats or answers while not necessarily being that much more powerful. Or rather, black needs to spend turns and mana digging for lands anyway, and it also has to survive long enough to get to 5-6 mana for haymakers, which doesn't really work out in practice often engouh. Being able to ramp a land on turn 2 would mean a lot to mono-black.
It's funny when you think about it - Sign in Blood and Night's Whisper are crazy powerful card draw, likely the most powerful in Pauper and closer to Ancestral Recall than blue ever gets. But black would actually dump them for a rampant growth which fetches a basic swamp into play if it could. It's a bit like how Demonic Tutor somehow always ends up looking for a land
Flavor-wise both black and green are about growth and spreading around, just for different reasons (to green growth is an end and a purpose unto itself, for black it's a means to an end and a result of being competitive towards anything around it). "Spreading the swamp" or "Spreading Corruption" is very easy to grok as a black thing, and as long as it's really limited in what it can get you (never anything other than a basic swamp) it'd be ok in that respect. And there's even precedent, but it costs 2BB to play, and black really needs to be doing other things with 4 lands in play and can't spend all of its mana on turn 4 (or even turn 3 for that matter) fetching that swamp. It needs one earlier to be able to play it's things while it digs / grinds to it's fifth or sixth land.
There, if WotC feels like shaking things up a bit, and the power of these effects (especially the first one) is not that big of an issue, those cards would certainly see play. If they're into printing more impactful commons and supporting Pauper, these things would be a godsend.
"Masques Block is the worst block ever! There's not one decent card in there! The whole internet say's so, you're literally the only person who ever said it was good!" - random noob in a conversation with an Eldrazi.