Pitiless Plunderer

Whenever another creature you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Reassembling Skeleton

{1}{B}: Return this card from your graveyard to the battlefield tapped.

Bog Initiate

Ashnod, Flesh Mechanist

Deathtouch
Whenever Ashnod, Flesh Mechanist attacks, you may sacrifice another creature. If you do, create a tapped Powerstone token.
{5}, Exile a creature card from your graveyard: Create a tapped 3/3 colorless Zombie artifact creature token.

Bloodsoaked Champion

Bloodsoaked Champion can't block.
Raid — {1}{B}: Return Bloodsoaked Champion from your graveyard to the battlefield. Activate only if you attacked this turn.

Ashnod's Altar

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.