Adrix and Nev, Twincasters: A lot of competition for this spot, but Adrix and Nevs ability to double all tokens, while having ward makes it notable as a strong card here
So now I can replace the venture into the dungeon text with choose one: create a Treasure token, target creature cant attack until your next turn, each player loses 2 life unless they sacrifice an artifact, a creature, or a land, put a +1/+1 counter on target creature, each opponent loses 1 life and you gain 1 life, or target creature gets -4/-0 until your next turn
If you have a lot of mana lying around and an Arcbound Ravager or Cranial Plating, you can squeeze an extra damage/poison counter out of a Blinkmoth Nexus by pumping the attacking Nexus with it and then activating it for an extra Plating power/another artifact to sacrifice to Ravager
I would expect to see Grief out of decks such as Jund, Deaths Shadow variants, Orzhov Taxes, and possibly even black-based combo or Reanimator decks
If you build a deck that can be outmuscled by a 3/3 or where youre running a low creature count (think like, 10-12), this wont fit in well, but in any kind of big monsters simic deck or a ramp deck, this is going to have a home