Alright, Pauper cards...
-Blink of an Eye a functional reprint of Into the Roil with way goofier art. Into the Roil does see a fair amount of Pauper play, but I don't think any decks want copies 5-8.
-Unwind seems amazing. One of the weaknesses of Delver is that it tends to choke its own mana pretty badly between Daze, Gush, and a low land count, so you can sneak things past counterwalls by just casting running threats. And Unwind can produce extra mana pretty easily in Teachings since it runs a lot of Dimir Aqueducts.
-Cabal Paladin seems like it has some potential in some kind of weird Eggs-like deck. There are a ton of cycles-from-play-for-free artifacts in Pauper and people have been experimenting a lot with Bleak Coven Vampires lately, so maybe some kind of Black Eggs could become a thing?
-Dark Bargain is basically a stretch limo version of Read the Bones which is a stretch limo version of Sign in Blood/Night's Whisper, which see plenty of play. Some control decks may want it. I'm slightly interested in the fact that I can tutor for it with Dimir House Guard in Pestilence. It doesn't dig quite as deep as Read the Bones though which does matter.
-Demonic Vigor may be a bit better than Undying Evil in Zuberas.
-Divest seems pretty powerful in general, I could see it seeing sideboard play.
-Rat Colony is probably better than the newly-legal-and-basically-unplayed Relentless Rats despite dying to a lot of extra common removal. Still not sure if it's good, but it can get deadly fast.
-Ghitu Lavamancer is
insane. I'm genuinely scared for how powerful this card is.
-Radiating Lightning is another board sweeper alongside Blazing Volley and Electrickery. It's a weird one, I'm not sure what deck would want it over those, but it seems pretty good on paper. Maybe it's main-deckable in Boros or something which could give it a niche?
-Adventurous Impulse is amazing in general and should see play in most if not all formats. Digging three cards is admittedly kind of shallow so it could miss occasionally in the wrong deck, but it makes a lot of sketchy hands easily keepable and smooths out inconsistent decks like Aristocrats quite a lot. Basically feels like a green Ponder to me, I can see it seeing a ton of play.
And as an honorable mention, the basic land in this set is incredible. Wizards has been hitting basic land out of the park lately in general with Amonkhet and Kaladesh, but these might be even nicer. It even has pretty Mountains which is often not the case.

I'll be on the lookout for foils of a solid half of the basics.