Disciple of the Vault

Whenever an artifact is put into a graveyard from the battlefield, you may have target opponent lose 1 life.

Candy Grapple

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
Target creature gets -3/-3 until end of turn. If this spell was bargained, that creature gets -5/-5 until end of turn instead.

Rowan's Grim Search

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
If this spell was bargained, look at the top four cards of your library, then put up to two of them back on top of your library in any order and the rest into your graveyard.
You draw two cards and you lose 2 life.

Cache Grab

Mill four cards. You may put a permanent card from among the cards milled this way into your hand. If you control a Squirrel or returned a Squirrel card to your hand this way, create a Food token. (To mill four cards, put the top four cards of your library into your graveyard. A Food token is an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Killer Service

When Killer Service enters, create a number of Food tokens equal to the number of opponents you have. (They're artifacts with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")
At the beginning of your end step, you may pay {2} and sacrifice a token. If you do, create a 4/4 green Rhino Warrior creature token.