Abrupt Decay

This spell can't be countered.
Destroy target nonland permanent with mana value 3 or less.

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Pattern of Rebirth

Enchant creature
When enchanted creature dies, that creature's controller may search their library for a creature card, put that card onto the battlefield, then shuffle.

Death

Return target creature card from your graveyard to the battlefield. You lose life equal to its mana value.

Life

All lands you control become 1/1 creatures until end of turn. They're still lands.

Life // Death

Slaughter Pact

Destroy target nonblack creature.
At the beginning of your next upkeep, pay {2}{B}. If you don't, you lose the game.

Viridian Revel

Whenever an artifact is put into an opponent's graveyard from the battlefield, you may draw a card.

Activated Sleeper

Flash
You may have Activated Sleeper enter as a copy of any creature card in a graveyard that was put there from the battlefield this turn, except it's a Phyrexian in addition to its other types.

Melira, Sylvok Outcast

You can't get poison counters.
Creatures you control can't have -1/-1 counters put on them.
Creatures your opponents control lose infect.

Sylvan Safekeeper

Sacrifice a land: Target creature you control gains shroud until end of turn. (It can't be the target of spells or abilities.)

Protean Hulk

When Protean Hulk dies, search your library for any number of creature cards with total mana value 6 or less, put them onto the battlefield, then shuffle.

Walking Ballista

Walking Ballista enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.

Deathrite Shaman

{T}: Exile target land card from a graveyard. Add one mana of any color.
{B}, {T}: Exile target instant or sorcery card from a graveyard. Each opponent loses 2 life.
{G}, {T}: Exile target creature card from a graveyard. You gain 2 life.

Elvish Spirit Guide

Exile Elvish Spirit Guide from your hand: Add {G}.

Elves of Deep Shadow

{T}: Add {B}. Elves of Deep Shadow deals 1 damage to you.

Delighted Halfling

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell, and that spell can't be countered.

Ad Nauseam

Reveal the top card of your library and put that card into your hand. You lose life equal to its mana value. You may repeat this process any number of times.

Natural Order

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

Fyndhorn Elves

Dryad Arbor

(Dryad Arbor isn't a spell, it's affected by summoning sickness, and it has "{T}: Add {G}.")

Cabal Therapy

Choose a nonland card name. Target player reveals their hand and discards all cards with that name.
Flashback—Sacrifice a creature. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Worldly Tutor

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

Mikaeus, the Unhallowed

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a Human deals damage to you, destroy it.
Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Scheming Symmetry

Choose two target players. Each of them searches their library for a card, then shuffles and puts that card on top.

Llanowar Elves

Disciple of the Vault

Whenever an artifact is put into a graveyard from the battlefield, you may have target opponent lose 1 life.

Culling Ritual

Destroy each nonland permanent with mana value 2 or less. Add {B} or {G} for each permanent destroyed this way.

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.

Sacrifice

As an additional cost to cast this spell, sacrifice a creature.
Add an amount of {B} equal to the sacrificed creature's mana value.

Elvish Mystic

Wake the Dead

Cast this spell only during combat on an opponent's turn.
Return X target creature cards from your graveyard to the battlefield. Sacrifice those creatures at the beginning of the next end step.

Carpet of Flowers

At the beginning of each of your main phases, if you haven't added mana with this ability this turn, you may add X mana of any one color, where X is the number of Islands target opponent controls.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)