Keiga, the Tide Star

Flying
When Keiga, the Tide Star dies, gain control of target creature.

Retaliate

Destroy all creatures that dealt damage to you this turn.

Forest

Time of Need

Search your library for a legendary creature card, reveal it, put it into your hand, then shuffle.

Fortified Village

As Fortified Village enters, you may reveal a Forest or Plains card from your hand. If you don't, Fortified Village enters tapped.
{T}: Add {G} or {W}.

Memorial to Unity

Memorial to Unity enters tapped.
{T}: Add {G}.
{2}{G}, {T}, Sacrifice Memorial to Unity: Look at the top five cards of your library. You may reveal a creature card from among them and put it into your hand. Then put the rest on the bottom of your library in a random order.

Engineered Explosives

Sunburst (This enters with a charge counter on it for each color of mana spent to cast it.)
{2}, Sacrifice Engineered Explosives: Destroy each nonland permanent with mana value equal to the number of charge counters on Engineered Explosives.

Replicate

Create a token that's a copy of target creature you control.

Repudiate

Counter target activated or triggered ability. (Mana abilities can't be targeted.)

Repudiate // Replicate

Negate

Llanowar Elves

Dragonlord Dromoka

This spell can't be countered.
Flying, lifelink
Your opponents can't cast spells during your turn.

Guardian Idol

Guardian Idol enters tapped.
{T}: Add {C}.
{2}: Guardian Idol becomes a 2/2 Golem artifact creature until end of turn.

Mirror Mockery

Enchant creature
Whenever enchanted creature attacks, you may create a token that's a copy of that creature. Exile that token at end of combat.

Island

Broken Bond

Destroy target artifact or enchantment. You may put a land card from your hand onto the battlefield.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Port Town

As Port Town enters, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters tapped.
{T}: Add {W} or {U}.

Dromoka's Command

Choose two —
• Prevent all damage target instant or sorcery spell would deal this turn.
• Target player sacrifices an enchantment of their choice.
• Put a +1/+1 counter on target creature.
• Target creature you control fights target creature you don't control.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Ojutai's Command

Choose two —
• Return target creature card with mana value 2 or less from your graveyard to the battlefield.
• You gain 4 life.
• Counter target creature spell.
• Draw a card.

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Declaration in Stone

Exile target creature and all other creatures its controller controls with the same name as that creature. That player investigates for each nontoken creature exiled this way.

Haven of the Spirit Dragon

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Dragon creature spell.
{2}, {T}, Sacrifice Haven of the Spirit Dragon: Return target Dragon creature card or Ugin planeswalker card from your graveyard to your hand.

Altered Ego

This spell can't be countered.
You may have Altered Ego enter as a copy of any creature on the battlefield, except it enters with X additional +1/+1 counters on it.

Hydroid Krasis

When you cast this spell, you gain half X life and draw half X cards. Round down each time.
Flying, trample
Hydroid Krasis enters with X +1/+1 counters on it.

Open the Armory

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Adventurous Impulse

Look at the top three cards of your library. You may reveal a creature or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Yosei, the Morning Star

Flying
When Yosei, the Morning Star dies, target player skips their next untap step. Tap up to five target permanents that player controls.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Hinterland Harbor

Hinterland Harbor enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.