Cybermen Squadron

Nonlegendary artifact creatures you control have myriad. (Whenever a creature with myriad attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Jet Medallion

Black spells you cast cost {1} less to cast.

Pactdoll Terror

Whenever this creature or another artifact you control enters, each opponent loses 1 life and you gain 1 life.

Doctor Doom

When Doctor Doom enters, create two 3/3 colorless Robot Villain artifact creature tokens named Doombot.
As long as you control an artifact creature or a Plan, Doctor Doom has indestructible.
At the beginning of your end step, you draw a card and lose 1 life.

Doom Reigns Supreme

Whenever a Villain you control enters, each opponent loses 1 life and you gain 1 life. Put a plan counter on this enchantment.
When the fifth plan counter is put on this enchantment, sacrifice it. When you do, target opponent exiles the top five cards of their library. You may cast up to two spells from among the exiled cards without paying their mana costs.