Emrakul, the Aeons Torn

This spell can't be countered.
When you cast this spell, take an extra turn after this one.
Flying, protection from spells that are one or more colors, annihilator 6
When Emrakul, the Aeons Torn is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

Archon of Cruelty

Flying
Whenever Archon of Cruelty enters or attacks, target opponent sacrifices a creature or planeswalker of their choice, discards a card, and loses 3 life. You draw a card and gain 3 life.

Undercity Sewers

({T}: Add {U} or {B}.)
Undercity Sewers enters tapped.
When Undercity Sewers enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Island

Petty Theft

Return target nonland permanent an opponent controls to its owner's hand.

Brazen Borrower

Flash
Flying
Brazen Borrower can block only creatures with flying.

Brazen Borrower // Petty Theft

Children of Korlis

Sacrifice Children of Korlis: You gain life equal to the life you've lost this turn. (Damage causes loss of life.)

Dauthi Voidwalker

Shadow (This creature can block or be blocked by only creatures with shadow.)
If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.
{T}, Sacrifice Dauthi Voidwalker: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Murktide Regent

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Flying
Murktide Regent enters with a +1/+1 counter on it for each instant and sorcery card exiled with it.
Whenever an instant or sorcery card leaves your graveyard, put a +1/+1 counter on Murktide Regent.

Underground Sea

Verdant Catacombs

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Dark Ritual

Grief

Menace
When Grief enters, target opponent reveals their hand. You choose a nonland card from it. That player discards that card.
Evoke—Exile a black card from your hand.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Atraxa, Grand Unifier

Flying, vigilance, deathtouch, lifelink
When Atraxa, Grand Unifier enters, reveal the top ten cards of your library. For each card type, you may put a card of that type from among the revealed cards into your hand. Put the rest on the bottom of your library in a random order. (Artifact, battle, creature, enchantment, instant, land, planeswalker, and sorcery are card types.)

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Daze

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
Counter target spell unless its controller pays {1}.

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Entomb

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

Swamp

Unmask

You may exile a black card from your hand rather than pay this spell's mana cost.
Target player reveals their hand. You choose a nonland card from it. That player discards that card.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Shallow Grave

Return the top creature card of your graveyard to the battlefield. That creature gains haste until end of turn. Exile it at the beginning of the next end step.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Griselbrand

Flying, lifelink
Pay 7 life: Draw seven cards.

Marsh Flats

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.