Contingency Plan

Surveil 5. (Look at the top five cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Sulfurous Springs

{T}: Add {C}.
{T}: Add {B} or {R}. This land deals 1 damage to you.

Otherworldly Gaze

Surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Efreet Flamepainter

Double strike
Whenever this creature deals combat damage to a player, you may cast target instant or sorcery card from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Living Lore

As this creature enters, exile an instant or sorcery card from your graveyard.
Living Lore's power and toughness are each equal to the exiled card's mana value.
Whenever this creature deals combat damage, you may sacrifice it. If you do, you may cast the exiled card without paying its mana cost.

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Swamp

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Magma Opus

Magma Opus deals 4 damage divided as you choose among any number of targets. Tap two target permanents. Create a 4/4 blue and red Elemental creature token. Draw two cards.
{U/R}{U/R}, Discard this card: Create a Treasure token.

Cruel Ultimatum

Target opponent sacrifices a creature of their choice, discards three cards, then loses 5 life. You return a creature card from your graveyard to your hand, draw three cards, then gain 5 life.

Island

Izzet Charm

Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• Izzet Charm deals 2 damage to target creature.
• Draw two cards, then discard two cards.

Collective Brutality

Escalate—Discard a card. (Pay this cost for each mode chosen beyond the first.)
Choose one or more —
• Target opponent reveals their hand. You choose an instant or sorcery card from it. That player discards that card.
• Target creature gets -2/-2 until end of turn.
• Target opponent loses 2 life and you gain 2 life.

Murderous Cut

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Destroy target creature.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. This land deals 1 damage to you.

Mountain

Inquisition of Kozilek

Target player reveals their hand. You choose a nonland card from it with mana value 3 or less. That player discards that card.

Sunken Hollow

({T}: Add {U} or {B}.)
This land enters tapped unless you control two or more basic lands.