Green Sun's Zenith

Search your library for a green creature card with mana value X or less, put it onto the battlefield, then shuffle. Shuffle Green Sun's Zenith into its owner's library.

Survival of the Fittest

{G}, Discard a creature card: Search your library for a creature card, reveal that card, put it into your hand, then shuffle.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Athreos, Shroud-Veiled

Indestructible
As long as your devotion to white and black is less than seven, Athreos isn't a creature.
At the beginning of your end step, put a coin counter on another target creature.
Whenever a creature with a coin counter on it dies or is put into exile, return that card to the battlefield under your control.

Virulent Plague

Diabolic Intent

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a card, put that card into your hand, then shuffle.

Enlightened Tutor

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.

Entomb

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

Chord of Calling

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Kathril, Aspect Warper

When Kathril, Aspect Warper enters, put a flying counter on any creature you control if a creature card in your graveyard has flying. Repeat this process for first strike, double strike, deathtouch, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance. Then put a +1/+1 counter on Kathril for each counter put on a creature this way.

Finale of Devastation

Search your library and/or graveyard for a creature card with mana value X or less and put it onto the battlefield. If you search your library this way, shuffle. If X is 10 or more, creatures you control get +X/+X and gain haste until end of turn.

Skullbriar, the Walking Grave

Haste
Whenever Skullbriar, the Walking Grave deals combat damage to a player, put a +1/+1 counter on it.
Counters remain on Skullbriar as it moves to any zone other than a player's hand or library.

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

Imperial Seal

Search your library for a card, then shuffle and put that card on top. You lose 2 life.