Encroaching Mycosynth does seem cool; we just recently got
Biotransference which does something similar, but this one opens up more options (also, being in blue, it can perhaps go in monoblue decks that want to use artifact tutors etc).
Skrelv's Hive seems pretty decent as a token generator. It may not quite be
Bitterblossom, but in white getting a steady source of 1/1s for e.g.
Skullclamp is nice. Likewise
Mirrex is I think the best token generator we have as a land (
Springjack Pasture has the added bonus of storing mana in goats, but at a pretty poor rate).
The proliferate cards also seem a lot more pushed this time. In the past, most of these were pretty expensive for what they did, except maybe
Tezzeret's Gambit (
Divination is not
great, but it's not a bad base to stick a proliferate on). Now we have
Cankerbloom (slightly worse Cathar Crusader but can proliferate instead),
Unnatural Restoration (not quite
Regrowth as it's permanents only, but close!),
Thirsting Roots (love these kinds of basically-just-a-land cards with utility),
Experimental Augury (nearly-Impulse), and so on. These all feel like sub-par-but-playable cards
before you add the proliferate rather than things where you're paying mostly for it. I am quite tempted to make an
Ezuri, Stalker of Spheres deck with no counters at all!
Argentum Masticore seems like a nice repeatable removal and discard outlet. It's kind of slow but it's another colourless removal for anything, so monocoloured decks might appreciate it for those annoying permanent types, and in particular I'm thinking e.g. monowhite reanimator - nothing super competitive, but a way to put big things into the graveyard whilst blowing stuff up seems pretty cool. Perhaps monored re-artificer(?), particularly when you also have
Containment Construct/
Conspiracy Theorist/madness and so on.
Oh and the dominuses (domini?) too, of course.
Drivnod, Carnage Dominus is a monoblack Teysa and I think slots into my Ratadrabik deck pretty well! Mondrak is tempting in the same deck though possibly a bit "win more" (but also being a sac outlet might edge it).