Consider

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

Breath Weapon

Breath Weapon deals 2 damage to each non-Dragon creature.

Weapon Rack

This artifact enters with three +1/+1 counters on it.
{T}: Move a +1/+1 counter from this artifact onto target creature. Activate only as a sorcery.

Thunder Magic

Tiered (Choose one additional cost.)
• Thunder — {0} — Thunder Magic deals 2 damage to target creature.
• Thundara — {3} — Thunder Magic deals 4 damage to target creature.
• Thundaga — {5}{R} — Thunder Magic deals 8 damage to target creature.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
This artifact enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on this artifact.

Hieroglyphic Illumination

Draw two cards.
Cycling {U} ({U}, Discard this card: Draw a card.)

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Burning Inquiry

Each player draws three cards, then discards three cards at random.

Ur-Golem's Eye

Protective Bubble

Enchant creature
Enchanted creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)

Prohibit

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Counter target spell if its mana value is 2 or less. If this spell was kicked, counter that spell if its mana value is 4 or less instead.

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Negate

Turn Aside

Counter target spell that targets a permanent you control.

Seal of Removal

Sacrifice this enchantment: Return target creature to its owner's hand.

The Lord Master of Hell

Starfall — Whenever The Lord Master of Hell attacks, it deals X damage to each opponent, where X is the number of noncreature, nonland cards in your graveyard.

The Emperor of Palamecia

{T}: Add {U} or {R}. Spend this mana only to cast a noncreature spell.
Whenever you cast a noncreature spell, if at least four mana was spent to cast it, put a +1/+1 counter on The Emperor of Palamecia. Then if it has three or more +1/+1 counters on it, transform it.

The Emperor of Palamecia // The Lord Master of Hell

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Snapback

You may exile a blue card from your hand rather than pay this spell's mana cost.
Return target creature to its owner's hand.

Ponder

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

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mountain

Grab the Prize

As an additional cost to cast this spell, discard a card.
Draw two cards. If the discarded card wasn't a land card, Grab the Prize deals 2 damage to each opponent.

Seize the Storm

Create a red Elemental creature token with trample and "This token's power and toughness are each equal to the number of instant and sorcery cards in your graveyard plus the number of cards with flashback you own in exile."
Flashback {6}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Dispel

Pirate's Pillage

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Blink of an Eye

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Return target nonland permanent to its owner's hand. If this spell was kicked, draw a card.

Counterspell

Swirling Sandstorm

Threshold — Swirling Sandstorm deals 5 damage to each creature without flying if there are seven or more cards in your graveyard.

Electric Revelation

As an additional cost to cast this spell, discard a card.
Draw two cards.
Flashback {3}{R} (You may cast this card from your graveyard for its flashback cost and any additional costs. Then exile it.)

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.

Island

Ecologist's Terrarium

When this artifact enters, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{2}, {T}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.

Volatile Fjord

({T}: Add {U} or {R}.)
This land enters tapped.

Mana Geyser

Add {R} for each tapped land your opponents control.

Firemind Vessel

This artifact enters tapped.
{T}: Add two mana of different colors.

Forge of Heroes

{T}: Add {C}.
{T}: Choose target commander that entered this turn. Put a +1/+1 counter on it if it's a creature and a loyalty counter on it if it's a planeswalker.

Into the Roil

Combat Tutorial

Target player draws two cards. Put a +1/+1 counter on up to one target creature you control.

Magic Damper

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it.

Thought Scour

Target player mills two cards.
Draw a card.

Fade Away

For each creature, its controller sacrifices a permanent of their choice unless they pay {1}.

Big Score

Clout of the Dominus

Enchant creature
As long as enchanted creature is blue, it gets +1/+1 and has shroud. (It can't be the target of spells or abilities.)
As long as enchanted creature is red, it gets +1/+1 and has haste.

Soul Read

Choose one —
• Counter target spell unless its controller pays {4}.
• Draw two cards.

Lórien Revealed

Draw three cards.
Islandcycling {1} ({1}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Fountainport Bell

When this artifact enters, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.
{1}, Sacrifice this artifact: Draw a card.

Ice Magic

Tiered (Choose one additional cost.)
• Blizzard — {0} — Return target creature to its owner's hand.
• Blizzara — {2} — Target creature's owner puts it on their choice of the top or bottom of their library.
• Blizzaga — {5}{U} — Target creature's owner shuffles it into their library.

Laughing Mad

Jilt

Kicker {1}{R} (You may pay an additional {1}{R} as you cast this spell.)
Return target creature to its owner's hand. If this spell was kicked, it deals 2 damage to another target creature.

Foil

You may discard an Island card and another card rather than pay this spell's mana cost.
Counter target spell.

Stealth Mission

Put two +1/+1 counters on target creature you control. That creature can't be blocked this turn.

Mystic Sanctuary

({T}: Add {U}.)
This land enters tapped unless you control three or more other Islands.
When this land enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Scattered Thoughts

Look at the top four cards of your library. Put two of those cards into your hand and the rest into your graveyard.

Intervene

Counter target spell that targets a creature.

Brass Knuckles

When you cast this spell, copy it. (The copy becomes a token.)
Equipped creature has double strike as long as two or more Equipment are attached to it.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Muddle the Mixture

Counter target instant or sorcery spell.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Fire of Orthanc

Destroy target artifact or land. Creatures without flying can't block this turn.

Rain of Revelation

Rewind

Counter target spell. Untap up to four lands.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Hypothesizzle

Draw two cards. Then you may discard a nonland card. When you do, Hypothesizzle deals 4 damage to target creature.

Behold the Multiverse

Scry 2, then draw two cards.
Foretell {1}{U} (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.)

Aboshan's Desire

Enchant creature
Enchanted creature has flying.
Threshold — Enchanted creature has shroud as long as there are seven or more cards in your graveyard. (It can't be the target of spells or abilities.)

Unexpected Windfall

Preordain

Scry 2, then draw a card. (To 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.)

Flight of Fancy

Enchant creature
When this Aura enters, draw two cards.
Enchanted creature has flying.

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Molten Tributary

Train of Thought

Replicate {1}{U} (When you cast this spell, copy it for each time you paid its replicate cost.)
Draw a card.

Syncopate

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sisay's Ring

Dreams of Laguna

Surveil 1, then draw a card. (To surveil 1, look at the top card of your library. You may put it into your graveyard.)
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Memory Lapse

Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into that player's graveyard.

Sulfurous Blast

Sulfurous Blast deals 2 damage to each creature and each player. If you cast this spell during your main phase, Sulfurous Blast deals 3 damage to each creature and each player instead.

Jailbreak Scheme

Spree (Choose one or more additional costs.)
+ {3} — Put a +1/+1 counter on target creature. It can't be blocked this turn.
+ {2} — Target artifact or creature's owner puts it on their choice of the top or bottom of their library.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.