Underground Sea

Dark Ritual

Demonic Counsel

Search your library for a Demon card, reveal it, put it into your hand, then shuffle.
Delirium — If there are four or more card types among cards in your graveyard, instead search your library for any card, put it into your hand, 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}.

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.

Mountain

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Griselbrand

Flying, lifelink
Pay 7 life: Draw seven cards.

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.

Damnable Pact

Target player draws X cards and loses X life.

Show and Tell

Each player may put an artifact, creature, enchantment, or land card from their hand onto the battlefield.

Sheoldred, the Apocalypse

Deathtouch
Whenever you draw a card, you gain 2 life.
Whenever an opponent draws a card, they lose 2 life.

Ob Nixilis, the Adversary

Casualty X. The copy isn't legendary and has starting loyalty X. (As you cast this spell, you may sacrifice a creature with power X. When you do, copy this spell. The copy becomes a token.)
+1: Each opponent loses 2 life unless they discard a card. If you control a Demon or Devil, you gain 2 life.
−2: Create a 1/1 red Devil creature token with "When this creature dies, it deals 1 damage to any target."
−7: Target player draws seven cards and loses 7 life.

Razorkin Needlehead

Razorkin Needlehead has first strike during your turn.
Whenever an opponent draws a card, Razorkin Needlehead deals 1 damage to them.

Swamp

Lotus Petal

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

Ponder

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

Troll of Khazad-dûm

Troll of Khazad-dûm can't be blocked except by three or more creatures.
Swampcycling {1} ({1}, Discard this card: Search your library for a Swamp card, reveal it, put it into your hand, then shuffle.)

Badlands

Bloodstained Mire

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