Scour the Laboratory

Delirium — This spell costs {2} less to cast if there are four or more card types among cards in your graveyard.
Draw three cards.

Captivating Gyre

Return up to three target creatures to their owners' hands.

Archipelagore

Mutate {5}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Whenever this creature mutates, tap up to X target creatures, where X is the number of times this creature has mutated. Those creatures don't untap during their controller's next untap step.

Magma Hellion

Assist (Another player can pay up to {6} of this spell's cost.)
Trample, haste

Wave-Wing Elemental

Flying
Landfall — Whenever a land you control enters, Wave-Wing Elemental gets +2/+2 until end of turn.

Accomplished Automaton

Fabricate 1 (When this creature enters, put a +1/+1 counter on it or create a 1/1 colorless Servo artifact creature token.)

Mahamoti Djinn

Flying (This creature can't be blocked except by creatures with flying or reach.)

Snow Day

Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.
Draw two cards, then discard a card.

Cinderheart Giant

Trample
When Cinderheart Giant dies, it deals 7 damage to a creature an opponent controls chosen at random.

Chartooth Cougar

{R}: Chartooth Cougar gets +1/+0 until end of turn.
Mountaincycling {2} ({2}, Discard this card: Search your library for a Mountain card, reveal it, put it into your hand, then shuffle.)

Spellweaver Duo

Assist (Another player can pay up to {6} of this spell's cost.)
When Spellweaver Duo enters, you may return target tapped creature to its owner's hand.

Doomskar Titan

When Doomskar Titan enters, creatures you control get +1/+0 and gain haste until end of turn.
Foretell {4}{R} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Prophet of the Peak

When Prophet of the Peak enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Creative Outburst

Creative Outburst deals 5 damage to any target. Look at the top five cards of your library. Put one of them into your hand and the rest on the bottom of your library in a random order.
{U/R}{U/R}, Discard Creative Outburst: Create a Treasure token.

Sea God's Scorn

Return up to three target creatures and/or enchantments to their owners' hands.

Mental Journey

Draw three cards.
Basic landcycling {1}{U} ({1}{U}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Ore-Scale Guardian

This spell costs {1} less to cast for each land card in your graveyard.
Flying, haste

Kuldotha Flamefiend

When Kuldotha Flamefiend enters, you may sacrifice an artifact. If you do, Kuldotha Flamefiend deals 4 damage divided as you choose among any number of targets.

Jhoira of the Ghitu

{2}, Exile a nonland card from your hand: Put four time counters on the exiled card. If it doesn't have suspend, it gains suspend. (At the beginning of your upkeep, remove a time counter from that card. When the last is removed, you may cast it without paying its mana cost. If it's a creature, it has haste.)

Ingenuity Engine

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
{1}, {T}, Sacrifice an artifact: Return target artifact you control to its owner's hand.

Gargadon

Trample
Suspend 4—{1}{R} (Rather than cast this card from your hand, you may pay {1}{R} and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)

Floodwaters

Return up to two target creatures to their owners' hands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Interpret the Signs

Scry 3, then reveal the top card of your library. Draw cards equal to that card's mana value. (To scry 3, look at the top three cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Razorfield Thresher

Swirling Torrent

Choose one or both —
• Put target creature on top of its owner's library.
• Return target creature to its owner's hand.

Roiling Waters

Return up to two target creatures your opponents control to their owners' hands. Target player draws two cards.

Meteor Golem

When Meteor Golem enters, destroy target nonland permanent an opponent controls.

Cinder Storm

Cinder Storm deals 7 damage to any target.

Riverwheel Aerialists

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Elemental Masterpiece

Create two 4/4 blue and red Elemental creature tokens.
{U/R}{U/R}, Discard Elemental Masterpiece: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Magmatic Sinkhole

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Magmatic Sinkhole deals 5 damage to target creature or planeswalker.

Seer's Lantern

{T}: Add {C}.
{2}, {T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Citywatch Sphinx

Flying
When Citywatch Sphinx dies, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Explosive Welcome

Explosive Welcome deals 5 damage to any target and 3 damage to any other target. Add {R}{R}{R}.

Confiscate

Enchant permanent
You control enchanted permanent.

Air-Cult Elemental

Flying
Whirlwind — When Air-Cult Elemental enters, return up to one other target creature to its owner's hand.

Earth-Cult Elemental

Siege Monster — When Earth-Cult Elemental enters, roll a d20.
1—9 | Each player sacrifices a permanent.
10—19 | Each opponent sacrifices a permanent.
20 | Each opponent sacrifices two permanents.

Lava Serpent

Haste
Cycling {2} ({2}, Discard this card: Draw a card.)

Sanctuary Smasher

First strike
Cycling {2}{R} ({2}{R}, Discard this card: Draw a card.)
When you cycle Sanctuary Smasher, put a first strike counter on target creature you control.

Book Devourer

Trample
Whenever Book Devourer deals combat damage to a player, you may discard all the cards in your hand. If you do, draw that many cards.

Millikin

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Bond of Passion

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Bond of Passion deals 2 damage to any other target.

Horizon Scholar

Flying
When Horizon Scholar enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Fiery Fall

Fiery Fall deals 5 damage to target creature.
Basic landcycling {1}{R} ({1}{R}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Prying Eyes

Prophetic Titan

Delirium — When Prophetic Titan enters, choose one. If there are four or more card types among cards in your graveyard, choose both instead.
• Prophetic Titan deals 4 damage to any target.
• Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in a random order.

Meteorite

When Meteorite enters, it deals 2 damage to any target.
{T}: Add one mana of any color.

Volcanic Dragon

Run Ashore

Choose one or both —
• The owner of target nonland permanent puts it on the top or bottom of their library.
• Return target nonland permanent to its owner's hand.

Slipstream Serpent

Slipstream Serpent can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Slipstream Serpent.
Morph {5}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Spreading Flames

Spreading Flames deals 6 damage divided as you choose among any number of target creatures.

Loreseeker's Stone

{3}, {T}: Draw three cards. This ability costs {1} more to activate for each card in your hand.

Ripscale Predator

Menace (This creature can't be blocked except by two or more creatures.)

Mountain

Inferno Jet

Inferno Jet deals 6 damage to target opponent or planeswalker.
Cycling {2} ({2}, Discard this card: Draw a card.)

Blood Feud

Target creature fights another target creature. (Each deals damage equal to its power to the other.)

Read the Tides

Choose one —
• Draw three cards.
• Return up to two target creatures to their owners' hands.

Opportunity

Revolutionist

When Revolutionist enters, return target instant or sorcery card from your graveyard to your hand.
Madness {3}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Island

Invading Manticore

When Invading Manticore enters, amass Zombies 2. (Put two +1/+1 counters on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

Scrapdiver Serpent

Scrapdiver Serpent can't be blocked as long as defending player controls an artifact.

Wingfold Pteron

Wingfold Pteron enters with your choice of a flying counter or a hexproof counter on it. (A creature with hexproof can't be the target of spells or abilities your opponents control.)

Bone Pit Brute

Menace (This creature can't be blocked except by two or more creatures.)
When Bone Pit Brute enters, target creature gets +4/+0 until end of turn.