Vector Asp

{B}: Vector Asp gains infect until end of turn. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Nyxathid

As Nyxathid enters the battlefield, choose an opponent.
Nyxathid gets -1/-1 for each card in the chosen player's hand.

Slither Blade

Counterspell

Eater of Days

Flying, trample
When Eater of Days enters the battlefield, you skip your next two turns.

Triton Shorestalker

Wall of Souls

Defender (This creature can't attack.)
Whenever Wall of Souls is dealt combat damage, it deals that much damage to target opponent or planeswalker.

Phage the Untouchable

When Phage the Untouchable enters the battlefield, if you didn't cast it from your hand, you lose the game.
Whenever Phage deals combat damage to a creature, destroy that creature. It can't be regenerated.
Whenever Phage deals combat damage to a player, that player loses the game.

Lazav, the Multifarious

When Lazav, the Multifarious enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{X}: Lazav, the Multifarious becomes a copy of target creature card in your graveyard with mana value X, except its name is Lazav, the Multifarious, it's legendary in addition to its other types, and it has this ability.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Unmarked Grave

Search your library for a nonlegendary card, put that card into your graveyard, then shuffle.

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Arcane Signet

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

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters the battlefield tapped unless you control three or more other Islands.
When Mystic Sanctuary enters the battlefield untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Ashiok, Dream Render

Spells and abilities your opponents control can't cause their controller to search their library.
−1: Target player mills four cards. Then exile each opponent's graveyard.

Likeness Looter

Flying
{T}: Draw a card, then discard a card.
{X}: Likeness Looter becomes a copy of target creature card in your graveyard with mana value X, except it has flying and this ability. Activate only as a sorcery.

Ornithopter

Entomb

Search your library for a card, put that card into your graveyard, then shuffle.

Necrotic Ooze

As long as Necrotic Ooze is on the battlefield, it has all activated abilities of all creature cards in all graveyards.

Rotting Regisaur

At the beginning of your upkeep, discard a card.

Phyrexian Obliterator

Trample
Whenever a source deals damage to Phyrexian Obliterator, that source's controller sacrifices that many permanents.

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

Invisible Stalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Invisible Stalker can't be blocked.

Hunted Horror

Trample
When Hunted Horror enters the battlefield, target opponent creates two 3/3 green Centaur creature tokens with protection from black.

Leveler

When Leveler enters the battlefield, exile all cards from your library.

Notion Thief

Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead that player skips that draw and you draw a card.

Sol Ring

Magus of the Bazaar

{T}: Draw two cards, then discard three cards.

Cavern Harpy

Flying
When Cavern Harpy enters the battlefield, return a blue or black creature you control to its owner's hand.
Pay 1 life: Return Cavern Harpy to its owner's hand.

Dauthi Voidwalker

Shadow (This creature can block or be blocked by only creatures with shadow.)
If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.
{T}, Sacrifice Dauthi Voidwalker: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Criminal Past

Commander creatures you own have menace and "This creature gets +X/+0, where X is the number of creature cards in your graveyard." (A creature with menace can't be blocked except by two or more creatures.)