Squee, the Immortal

You may cast Squee, the Immortal from your graveyard or from exile.

Sol Ring

Ashad, the Lone Cyberman

The first nonlegendary artifact spell you cast each turn has casualty 2. (As you cast it, you may sacrifice a creature with power 2 or greater. When you do, copy it. A copy of an artifact spell becomes a token.)
Whenever you sacrifice another creature, put a +1/+1 counter on Ashad, the Lone Cyberman.

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.")