Karn, Scion of Urza

+1: Reveal the top two cards of your library. An opponent chooses one of them. Put that card into your hand and exile the other with a silver counter on it.
−1: Put a card you own with a silver counter on it from exile into your hand.
−2: Create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."

Strict Proctor

Flying
Whenever a permanent entering causes a triggered ability to trigger, counter that ability unless its controller pays {2}.

Recruiter of the Guard

When this creature enters, you may search your library for a creature card with toughness 2 or less, reveal it, put it into your hand, then shuffle.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Phyrexian Dreadnought

Trample
When this creature enters, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.

Karn, the Great Creator

Activated abilities of artifacts your opponents control can't be activated.
+1: Until your next turn, up to one target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value.
−2: You may reveal an artifact card you own from outside the game or choose a face-up artifact card you own in exile. Put that card into your hand.

Lotus Field

Hexproof
This land enters tapped.
When this land enters, sacrifice two lands.
{T}: Add three mana of any one color.

Torpor Orb

Creatures entering don't cause abilities to trigger.

Myr Retriever

When this creature dies, return another target artifact card from your graveyard to your hand.

Eater of Days

Flying, trample
When this creature enters, you skip your next two turns.

Leveler

When this creature enters, exile all cards from your library.

Oswald Fiddlebender

Magical Tinkering — {W}, {T}, Sacrifice an artifact: Search your library for an artifact card with mana value equal to 1 plus the sacrificed artifact's mana value, put it onto the battlefield, then shuffle. Activate only as a sorcery.

Scrap Trawler

Whenever this creature dies or another artifact you control is put into a graveyard from the battlefield, return to your hand target artifact card in your graveyard with lesser mana value.

Lotus Vale

If this land would enter, sacrifice two untapped lands instead. If you do, put this land onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add three mana of any one color.

Karn Liberated

+4: Target player exiles a card from their hand.
−3: Exile target permanent.
−14: Restart the game, leaving in exile all non-Aura permanent cards exiled with Karn. Then put those cards onto the battlefield under your control.

Mimic Vat

Imprint — Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with this artifact to its owner's graveyard.
{3}, {T}: Create a token that's a copy of a card exiled with this artifact. It gains haste. Exile it at the beginning of the next end step.