Arbaaz Mir

Whenever Arbaaz Mir or another nontoken historic permanent you control enters, Arbaaz Mir deals 1 damage to each opponent and you gain 1 life. (Artifacts, legendaries, and Sagas are historic.)

Disenchant

Bell Borca, Spectral Sergeant

Note the mana value of each card as it's put into exile.
Bell Borca, Spectral Sergeant's power is equal to the greatest number noted for it this turn.
At the beginning of your upkeep, exile the top card of your library. You may play that card this turn.

Sephara, Sky's Blade

You may pay {W} and tap four untapped creatures you control with flying rather than pay this spell's mana cost.
Flying, lifelink
Other creatures you control with flying have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Prison Sentence

Enchant creature
When Prison Sentence enters, scry 2.
Enchanted creature can't attack or block, and its activated abilities can't be activated.

Éowyn, Fearless Knight

Haste
When Éowyn, Fearless Knight enters, exile target creature an opponent controls with greater power. Legendary creatures you control gain protection from each of that creature's colors until end of turn.

Flaming Fist

Commander creatures you own have "Whenever this creature attacks, it gains double strike until end of turn."

Duchess, Wayward Tavernkeep

Hunters for Hire — Whenever a creature you control deals combat damage to a player, put a quest counter on it.
{1}, Remove a quest counter from a permanent you control: Create a Junk token. (It's an artifact with "{T}, Sacrifice this artifact: Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.")

Erkenbrand, Lord of Westfold

Whenever Erkenbrand, Lord of Westfold or another Human you control enters, creatures you control get +1/+0 until end of turn.

Mishra's Domination

Enchant creature
As long as you control enchanted creature, it gets +2/+2. Otherwise, it can't block.

Mountain

Goro-Goro, Disciple of Ryusei

{R}: Creatures you control gain haste until end of turn.
{3}{R}{R}: Create a 5/5 red Dragon Spirit creature token with flying. Activate only if you control an attacking modified creature. (Equipment, Auras you control, and counters are modifications.)

Ertha Jo, Frontier Mentor

When Ertha Jo, Frontier Mentor enters, create a 1/1 red Mercenary creature token with "{T}: Target creature you control gets +1/+0 until end of turn. Activate only as a sorcery."
Whenever you activate an ability that targets a creature or player, copy that ability. You may choose new targets for the copy.

Skoa, Embermage

When Skoa, Embermage enters, it deals 4 damage to any target.
Grandeur — Discard another card named Skoa, Embermage, Sacrifice two Mountains: Skoa deals 4 damage to any target.

Legion Stronghold

Legion Stronghold enters tapped.
{T}: Add {R} or {W}.

Legion Leadership

Until end of turn, double target creature's power and it gains first strike.

Legion Leadership // Legion Stronghold

Jenny, Generated Anomaly

Double strike
Whenever Jenny deals combat damage to a player, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Laelia, the Blade Reforged

Haste
Whenever Laelia, the Blade Reforged attacks, exile the top card of your library. You may play that card this turn.
Whenever one or more cards are put into exile from your library and/or your graveyard, put a +1/+1 counter on Laelia.

Bosh, Iron Golem

Trample
{3}{R}, Sacrifice an artifact: Bosh, Iron Golem deals damage equal to the sacrificed artifact's mana value to any target.

Éowyn, Lady of Rohan

At the beginning of combat on your turn, target creature gains your choice of first strike or vigilance until end of turn. If that creature is equipped, it gains first strike and vigilance until end of turn instead.
Equip abilities you activate cost {1} less to activate.

Heroes' Podium

Each legendary creature you control gets +1/+1 for each other legendary creature you control.
{X}, {T}: Look at the top X cards of your library. You may reveal a legendary creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Baird, Steward of Argive

Vigilance
Creatures can't attack you or planeswalkers you control unless their controller pays {1} for each of those creatures.

Eye of Vecna

When Eye of Vecna enters, you draw a card and you lose 2 life.
At the beginning of your upkeep, you may pay {2}. If you do, you draw a card and you lose 2 life.

Alexios, Deimos of Kosmos

Trample
Alexios, Deimos of Kosmos attacks each combat if able, can't be sacrificed, and can't attack its owner.
At the beginning of each player's upkeep, that player gains control of Alexios, untaps it, and puts a +1/+1 counter on it. It gains haste until end of turn.

Rorix Bladewing

Ezio, Brash Novice

Whenever Ezio, Brash Novice attacks, put a +1/+1 counter on it.
As long as Ezio has two or more counters on it, it has first strike and is an Assassin in addition to its other types.

Boros Garrison

Boros Garrison enters tapped.
When Boros Garrison enters, return a land you control to its owner's hand.
{T}: Add {R}{W}.

Plains

Djeru and Hazoret

As long as you have one or fewer cards in hand, Djeru and Hazoret has vigilance and haste.
Whenever Djeru and Hazoret attacks, look at the top six cards of your library. You may exile a legendary creature card from among them. Put the rest on the bottom of your library in a random order. Until end of turn, you may cast the exiled card without paying its mana cost.

Moira Brown, Guide Author

When Moira Brown, Guide Author enters, create a colorless Equipment artifact token named Wasteland Survival Guide with "Equipped creature gets +1/+1 for each quest counter among permanents you control" and equip {1}.
Whenever you attack, put a quest counter on target nonland permanent you control.

Popular Entertainer

Commander creatures you own have "Whenever one or more creatures you control deal combat damage to a player, goad target creature that player controls." (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Jor Kadeen, the Prevailer

First strike
Metalcraft — Creatures you control get +3/+0 as long as you control three or more artifacts.