Mindslaver

{4}, {T}, Sacrifice Mindslaver: You control target player during that player's next turn. (You see all cards that player could see and make all decisions for the player.)

Unwinding Clock

Untap all artifacts you control during each other player's untap step.

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Palladium Myr

Crown of Empires

{3}, {T}: Tap target creature. Gain control of that creature instead if you control artifacts named Scepter of Empires and Throne of Empires.

Strip Mine

{T}: Add {C}.
{T}, Sacrifice this land: Destroy target land.

Scepter of Empires

{T}: This artifact deals 1 damage to target player or planeswalker. It deals 3 damage instead if you control artifacts named Crown of Empires and Throne of Empires.

Pili-Pala

Flying
{2}, {Q}: Add one mana of any color. ({Q} is the untap symbol.)

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put this artifact on top of its owner's library.

Cloud Key

As this artifact enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Marvin, Murderous Mimic

Marvin has all activated abilities of creatures you control that don't have the same name as this creature.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Ancient Tomb

{T}: Add {C}{C}. This land deals 2 damage to you.

Mystic Forge

You may look at the top card of your library any time.
You may cast artifact spells and colorless spells from the top of your library.
{T}, Pay 1 life: Exile the top card of your library.

Wastes

Throne of Empires

{1}, {T}: Create a 1/1 white Soldier creature token. Create five of those tokens instead if you control artifacts named Crown of Empires and Scepter of Empires.

The One Ring

Indestructible
When The One Ring enters, if you cast it, you gain protection from everything until your next turn.
At the beginning of your upkeep, you lose 1 life for each burden counter on The One Ring.
{T}: Put a burden counter on The One Ring, then draw a card for each burden counter on The One Ring.