Anowon, the Ruin Thief

Other Rogues you control get +1/+1.
Whenever one or more Rogues you control deal combat damage to a player, that player mills a card for each 1 damage dealt to them. If the player mills at least one creature card this way, you draw a card. (To mill a card, a player puts the top card of their library into their graveyard.)

Anticipate

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Dimir Signet

Champion's Helm

Equipped creature gets +2/+2.
As long as equipped creature is legendary, it has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Wayfarer's Bauble

{2}, {T}, Sacrifice this artifact: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Helm of Awakening

Xanathar, Guild Kingpin

At the beginning of your upkeep, choose target opponent. Until end of turn, that player can't cast spells, you may look at the top card of their library any time, you may play the top card of their library, and you may spend mana as though it were mana of any color to cast spells this way.

Annex

Enchant land (Target a land as you cast this. This card enters attached to that land.)
You control enchanted land.

Arcane Encyclopedia

Alhammarret, High Arbiter

Flying
As Alhammarret enters, each opponent reveals their hand. You choose the name of a nonland card revealed this way.
Your opponents can't cast spells with the chosen name (as long as this creature is on the battlefield).

Helm of Possession

You may choose not to untap this artifact during your untap step.
{2}, {T}, Sacrifice a creature: Gain control of target creature for as long as you control this artifact and this artifact remains tapped.

Coralhelm Guide

{4}{U}: Target creature can't be blocked this turn.

Aether Vial

At the beginning of your upkeep, you may put a charge counter on this artifact.
{T}: You may put a creature card with mana value equal to the number of charge counters on this artifact from your hand onto the battlefield.

Bone Offering

Create a tapped 4/1 black Skeleton creature token with menace. (Then exile this card. You may cast the artifact later from exile.)

Altar of Bhaal

{2}{B}, {T}, Exile a creature you control: Return target creature card from your graveyard to the battlefield. Activate only as a sorcery.

Altar of Bhaal // Bone Offering

Agadeem, the Undercrypt

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {B}.

Agadeem's Awakening

Return from your graveyard to the battlefield any number of target creature cards that each have a different mana value X or less.

Agadeem's Awakening // Agadeem, the Undercrypt

Agatha's Soul Cauldron

You may spend mana as though it were mana of any color to activate abilities of creatures you control.
Creatures you control with +1/+1 counters on them have all activated abilities of all creature cards exiled with Agatha's Soul Cauldron.
{T}: Exile target card from a graveyard. When a creature card is exiled this way, put a +1/+1 counter on target creature you control.

Agent of Treachery

When this creature enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Hakka, Whispering Raven

Flying
Whenever Hakka deals combat damage to a player, return it to its owner's hand, then scry 2.

Alrund, God of the Cosmos

Alrund gets +1/+1 for each card in your hand and each foretold card you own in exile.
At the beginning of your end step, choose a card type, then reveal the top two cards of your library. Put all cards of the chosen type revealed this way into your hand and the rest on the bottom of your library in any order.

Alrund, God of the Cosmos // Hakka, Whispering Raven

Ancient Brass Dragon

Flying
Whenever this creature deals combat damage to a player, roll a d20. When you do, put any number of target creature cards with total mana value X or less from graveyards onto the battlefield under your control, where X is the result.

Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Gitaxian Mindstinger

Deathtouch
Whenever this creature deals combat damage to a player or battle, draw a card.

Aetherblade Agent

Deathtouch
{4}{U/P}: Transform this creature. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.)

Aetherblade Agent // Gitaxian Mindstinger

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Draugr's Helm

When this Equipment enters, you may pay {2}{B}. If you do, create a 2/2 black Zombie Berserker creature token, then attach this Equipment to it.
Equipped creature gets +2/+2 and has menace. (It can't be blocked except by two or more creatures.)
Equip {4}

Acquire

Search target opponent's library for an artifact card and put that card onto the battlefield under your control. Then that player shuffles.