Death and Taxes
One recent build of Death and Taxes on Magic Online played a full playset of Vryn Wingmare and a singleton Archangel of Tithes. The Wingmare is a card I’ve seen as having potential in that kind of deck, and apparently, it worked in this build as it went 4-0 in a Modern Daily. The Archangel is a good card, too, and fits perfectly into this archetype. This particular deck also played a singleton copy of Hallowed Moonlight in the sideboard - probably for the Splinter Twin or Living End matchups.
There was one other Death and Taxes build that played 2 copies of the Wingmare and an Archangel of Tithes in the sideboard. It went 3-1 in a daily. So while the Wingmare and Archangel haven’t gained widespread acceptance yet in the format, there’s a good chance that they work their way in.
Dwynen’s Elite didn’t have a strong showing at Pro Tour Magic Origins, but at least one copy has been showing up in Modern Elf builds. This 4-0 Elves list has a full play-set jammed into Modern Elf decks. It also features 3 copies of Sylvan Messenger. The Messenger has long been good in Legacy, but now that it’s been printed in a Modern set (it was in Apocalypse and only reprinted in the modern border in the Elves vs Goblins Duel Deck), it may soon make an impact on the Modern format, too. The card advantage given by the Messenger seems worth it.
It has been widely thought that the new Origins Merfolk Harbinger of the Tides would see some decent Modern play. Most seem to still prefer Tidebinder Mage, which taps down only red and green permanents. It would seem that the creature bounce, especially off of an Aether Vial, would be powerful in that format. This 3-1 Modern Daily List did run 3 copies, and this 3-1 Merfolk list ran a full play-set.
The interesting mythic Day’s Undoing showed up in this 4-color list in Modern. However, the mythic also showed up in Legacy Affinity. It’s quite possible that the card sees play in Modern Affinity, as well, once the proper balance is found.
Goblin Piledriver hasn’t seen quite a lot of Modern play just yet, but this 3-1 Modern Daily White/Red Aggro list did run a full playset. It has seen renewed Legacy play, even though it was long already legal there.
While Magic Origins hasn’t had quite the impact that the Khans of Tarkir block has had on Modern, there are signs that there are some cards that will be seeing plenty of play in the format in the long-term.