Mana Echoes

Whenever a creature enters, you may add an amount of {C} equal to the number of creatures you control that share a creature type with it.

Mountain

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Icewind Stalwart

Protection Fighting Style — When Icewind Stalwart enters, exile up to one target non-Warrior creature you control, then return it to the battlefield under its owner's control.

Village Bell-Ringer

Flash (You may cast this spell any time you could cast an instant.)
When Village Bell-Ringer enters, untap all creatures you control.

Spirited Companion

When Spirited Companion enters, draw a card.

Gird for Battle

Put a +1/+1 counter on each of up to two target creatures.

Hyena Umbra

Enchant creature
Enchanted creature gets +1/+1 and has first strike.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Star Athlete

Menace
Whenever Star Athlete attacks, choose up to one target nonland permanent. Its controller may sacrifice it. If they don't, Star Athlete deals 5 damage to that player.
Blitz {3}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Umbral Mantle

Equipped creature has "{3}, {Q}: This creature gets +2/+2 until end of turn." ({Q} is the untap symbol.)
Equip {0}

Prop Room

Untap each creature you control during each other player's untap step.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Dazzling Theater

Creature spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a creature spell pays for {1} or one mana of that creature's color.)
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Dazzling Theater // Prop Room

Inspiring Vantage

Inspiring Vantage enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {W}.

Balefire Liege

Other red creatures you control get +1/+1.
Other white creatures you control get +1/+1.
Whenever you cast a red spell, Balefire Liege deals 3 damage to target player or planeswalker.
Whenever you cast a white spell, you gain 3 life.

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Agrus Kos, Wojek Veteran

Whenever Agrus Kos, Wojek Veteran attacks, attacking red creatures get +2/+0 and attacking white creatures get +0/+2 until end of turn.

Dauntless Avenger

Whenever Dauntless Avenger attacks, return target creature card with mana value 2 or less from your graveyard to the battlefield tapped and attacking.

Bereaved Survivor

When another creature you control dies, transform Bereaved Survivor.

Bereaved Survivor // Dauntless Avenger

Magus of the Moon

Resurgence

Creatures you control gain first strike and vigilance until end of turn. After this main phase, there is an additional combat phase followed by an additional main phase.

Response

Response deals 5 damage to target attacking or blocking creature.

Response // Resurgence

Temporal Isolation

Flash
Enchant creature
Enchanted creature has shadow. (It can block or be blocked by only creatures with shadow.)
Prevent all damage that would be dealt by enchanted creature.

Cathar Commando

Flash
{1}, Sacrifice Cathar Commando: Destroy target artifact or enchantment.

Aurelia, Exemplar of Justice

Flying
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
At the beginning of combat on your turn, choose up to one target creature you control. Until end of turn, that creature gets +2/+0, gains trample if it's red, and gains vigilance if it's white.

Felidar Guardian

When Felidar Guardian enters, you may exile another target permanent you control, then return that card to the battlefield under its owner's control.

Intervention

Intervention deals 3 damage to any target and you gain 3 life.

Integrity

Target creature gets +2/+2 until end of turn.

Integrity // Intervention

The Jolly Balloon Man

Haste
{1}, {T}: Create a token that's a copy of another target creature you control, except it's a 1/1 red Balloon creature in addition to its other colors and types and it has flying and haste. Sacrifice it at the beginning of the next end step. Activate only as a sorcery.

Staff of Domination

{1}: Untap Staff of Domination.
{2}, {T}: You gain 1 life.
{3}, {T}: Untap target creature.
{4}, {T}: Tap target creature.
{5}, {T}: Draw a card.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Demotion

Enchant creature
Enchanted creature can't block, and its activated abilities can't be activated.

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Pacifism

Enchant creature
Enchanted creature can't attack or block.

Angelfire Ignition

Put two +1/+1 counters on target creature. It gains vigilance, trample, lifelink, indestructible, and haste until end of turn.
Flashback {2}{R}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

General Ferrous Rokiric

Hexproof from monocolored
Whenever you cast a multicolored spell, create a 4/4 red and white Golem artifact creature token.

Journey to Nowhere

When Journey to Nowhere enters, exile target creature.
When Journey to Nowhere leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Restoration Angel

Flash
Flying
When Restoration Angel enters, you may exile target non-Angel creature you control, then return that card to the battlefield under your control.

Containment Priest

Flash
If a nontoken creature would enter and it wasn't cast, exile it instead.

Sunrise Cavalier

Trample, haste
If it's neither day nor night, it becomes day as Sunrise Cavalier enters.
Whenever day becomes night or night becomes day, put a +1/+1 counter on target creature you control.

Impact Tremors

Whenever a creature you control enters, Impact Tremors deals 1 damage to each opponent.

Akroan Hoplite

Whenever Akroan Hoplite attacks, it gets +X/+0 until end of turn, where X is the number of attacking creatures you control.