You could play Bankrupt in Blood, Plumb the Forbidden, or Skulltap in this slot
whenever Assembled Alphas is blocked by an opponent's creature, or blocks an opponent's creature, it does 3 damage to both the creature's controller and the creature that it blocked or was blocked by
The mechanic backup shines here as a way to pump creatures and add abilities to them, and rares like Boon-Bringer Valkyrie and Silverback Elder are game-winning bombs
Cycling ( , Discard this card: Draw a card.) Cid, Timeless Artificer Rarity: Uncommon TYPE: Legendary Creature SUBTYPE: Human Artificer CMC: 4 Mana cost: USD: $3.20 EUR: 3.03 TIX: 0.23 EDHREC RANK: 12038 (4/4) Artifact creatures and Heroes you control get +1/+1 for each Artificer you control and each Artificer card in your graveyard
Carrion Cruiser I imagine Carrion Cruiser mostly sees play in Peasant Cubes, but a Gravedigger that supplies its own fodder could probably find a home in slightly stronger Cubes as well