Consider

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

Concoct

Surveil 3, then return a creature card from your graveyard to the battlefield.

Connive

Gain control of target creature with power 2 or less.

Connive // Concoct

Marvo, Deep Operative

Whenever Marvo, Deep Operative attacks, clash with defending player. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)
Whenever you win a clash, draw a card. Then you may cast a spell from your hand with mana value 8 or less without paying its mana cost.

Pontiff of Blight

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Other creatures you control have extort. (If a creature has multiple instances of extort, each triggers separately.)

Nesting Grounds

{T}: Add {C}.
{1}, {T}: Move a counter from target permanent you control onto another target permanent. Activate only as a sorcery.

Drowned Catacomb

Drowned Catacomb enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Drownyard Temple

{T}: Add {C}.
{3}: Return Drownyard Temple from your graveyard to the battlefield tapped.

Vizier of Many Faces

You may have Vizier of Many Faces enter as a copy of any creature on the battlefield, except if Vizier of Many Faces was embalmed, the token has no mana cost, it's white, and it's a Zombie in addition to its other types.
Embalm {3}{U}{U}

Necromancy

You may cast Necromancy as though it had flash. If you cast it any time a sorcery couldn't have been cast, the controller of the permanent it becomes sacrifices it at the beginning of the next cleanup step.
When Necromancy enters, if it's on the battlefield, it becomes an Aura with "enchant creature put onto the battlefield with Necromancy." Put target creature card from a graveyard onto the battlefield under your control and attach Necromancy to it. When Necromancy leaves the battlefield, that creature's controller sacrifices it.

Dispersal

Each opponent returns a nonland permanent they control with the highest mana value among permanents they control to its owner's hand, then discards a card.

Discovery

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

Discovery // Dispersal

Fetid Pools

({T}: Add {U} or {B}.)
Fetid Pools enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Disinformation Campaign

When Disinformation Campaign enters, you draw a card and each opponent discards a card.
Whenever you surveil, return Disinformation Campaign to its owner's hand.

Baleful Strix

Flying, deathtouch
When Baleful Strix enters, draw a card.

Amphin Mutineer

When Amphin Mutineer enters, exile up to one target non-Salamander creature. That creature's controller creates a 4/3 blue Salamander Warrior creature token.
Encore {4}{U}{U} ({4}{U}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Eye of Duskmantle

Flying, lifelink
You may play lands and cast spells from among cards in your graveyard you've surveilled this turn. If you cast a spell this way, you pay life equal to its mana value rather than paying its mana cost.

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Whispering Snitch

Whenever you surveil for the first time each turn, Whispering Snitch deals 1 damage to each opponent and you gain 1 life.

Gossip's Talent

(Gain the next level as a sorcery to add its ability.)
Whenever a creature you control enters, surveil 1.
{1}{U}: Level 2
Whenever you attack, target attacking creature with power 3 or less can't be blocked this turn.
{3}{U}: Level 3
Whenever a creature you control deals combat damage to a player, you may exile it, then return it to the battlefield under its owner's control.

Sphinx of the Second Sun

Flying
At the beginning of each of your postcombat main phases, there is an additional beginning phase after this phase. (The beginning phase includes the untap, upkeep, and draw steps.)

Dimir Spybug

Flying
Menace (This creature can't be blocked except by two or more creatures.)
Whenever you surveil, put a +1/+1 counter on Dimir Spybug.

The Grim Captain's Locker

{T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Until end of turn, each creature card in your graveyard gains "Escape—{3}{B}, Exile four other cards from your graveyard." (You may cast a card with escape from your graveyard for its escape cost.)

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Dogged Detective

When Dogged Detective enters, 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.)
Whenever an opponent draws their second card each turn, you may return Dogged Detective from your graveyard to your hand.

Rise of the Dark Realms

Put all creature cards from all graveyards onto the battlefield under your control.

Enhanced Surveillance

You may look at an additional two cards each time you surveil.
Exile Enhanced Surveillance: Shuffle your graveyard into your library.

Shriekmaw

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
When Shriekmaw enters, destroy target nonartifact, nonblack creature.
Evoke {1}{B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Auton Soldier

You may have Auton Soldier enter as a copy of any creature on the battlefield, except it isn't legendary, is an artifact in addition to its other types, and has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Mockingbird

Flying
You may have Mockingbird enter as a copy of any creature on the battlefield with mana value less than or equal to the amount of mana spent to cast Mockingbird, except it's a Bird in addition to its other types and it has flying.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Doom Whisperer

Flying, trample
Pay 2 life: 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.)

Conduit Pylons

When Conduit Pylons enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Nightveil Sprite

Flying
Whenever Nightveil Sprite attacks, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Choked Estuary

As Choked Estuary enters, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters tapped.
{T}: Add {U} or {B}.

Sol Ring

Massacre Wurm

When Massacre Wurm enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Mission Briefing

Surveil 2, then choose an instant or sorcery card in your graveyard. You may cast it this turn. If that spell would be put into your graveyard, exile it instead. (To 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.)

Copy Catchers

Flying
Whenever you surveil, you may pay {1}{U}. If you do, create a token that's a copy of Copy Catchers.

Mirko, Obsessive Theorist

Flying, vigilance
Whenever you surveil, put a +1/+1 counter on Mirko, Obsessive Theorist.
At the beginning of your end step, you may return target creature card with power less than Mirko's from your graveyard to the battlefield with a finality counter on it. (If it would die, exile it instead.)

Rona, Tolarian Obliterator

Trample
Whenever a source deals damage to Rona, Tolarian Obliterator, that source's controller exiles a card from their hand at random. If it's a land card, you may put it onto the battlefield under your control. Otherwise, you may cast it without paying its mana cost.

Rona, Herald of Invasion

Whenever you cast a legendary spell, untap Rona, Herald of Invasion.
{T}: Draw a card, then discard a card.
{5}{B/P}: Transform Rona. Activate only as a sorcery. ({B/P} can be paid with either {B} or 2 life.)

Rona, Herald of Invasion // Rona, Tolarian Obliterator

Azcanta, the Sunken Ruin

(Transforms from Search for Azcanta.)
{T}: Add {U}.
{2}{U}, {T}: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Search for Azcanta

At the beginning of your upkeep, surveil 1. Then if you have seven or more cards in your graveyard, you may transform Search for Azcanta. (Look at the top card of your library. You may put that card into your graveyard.)

Search for Azcanta // Azcanta, the Sunken Ruin

Tainted Isle

{T}: Add {C}.
{T}: Add {U} or {B}. Activate only if you control a Swamp.

Hostile Desert

{T}: Add {C}.
{2}, Exile a land card from your graveyard: Hostile Desert becomes a 3/4 Elemental creature until end of turn. It's still a land.

Counterpoint

Counter target spell. You may cast a creature, instant, sorcery, or planeswalker spell from your graveyard with mana value less than or equal to that spell's mana value without paying its mana cost.

Sunken Hollow

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

Curate

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.)
Draw a card.

Foreboding Steamboat

When Foreboding Steamboat enters, each player chooses two nontoken, non-Vehicle creatures they control. Exile them until Foreboding Steamboat leaves the battlefield.
Whenever Foreboding Steamboat attacks, put a card exiled with it into its owner's graveyard. If you do, investigate.
Crew 2

Spellgyre

Choose one —
• Counter target spell.
• Surveil 2, then draw two cards. (To 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.)

Proft's Eidetic Memory

When Proft's Eidetic Memory enters, draw a card.
You have no maximum hand size.
At the beginning of combat on your turn, if you've drawn more than one card this turn, put X +1/+1 counters on target creature you control, where X is the number of cards you've drawn this turn minus one.

Diresight

Surveil 2, then draw two cards. You lose 2 life. (To 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.)

River of Tears

{T}: Add {U}. If you played a land this turn, add {B} instead.

Likeness Looter

Flying
{T}: Draw a card, then discard a card.
{X}: Likeness Looter becomes a copy of target creature card in your graveyard with mana value X, except it has flying and this ability. Activate only as a sorcery.

Reanimate

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

Price of Fame

This spell costs {2} less to cast if it targets a legendary creature.
Destroy target creature.
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.)

Swamp

Sinister Starfish

{T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Final-Word Phantom

Flash
Flying
During each opponent's end step, you may cast spells as though they had flash.

Notion Rain

Surveil 2, then draw two cards. Notion Rain deals 2 damage to you. (To 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.)

Grave Titan

Deathtouch
Whenever Grave Titan enters or attacks, create two 2/2 black Zombie creature tokens.

Darkwater Catacombs

Pile On

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy target creature or planeswalker. 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.)

Port of Karfell

Port of Karfell enters tapped.
{T}: Add {U}.
{3}{U}{B}{B}, {T}, Sacrifice Port of Karfell: Mill four cards, then return a creature card from your graveyard to the battlefield tapped. (To mill a card, put the top card of your library into your graveyard.)

Arcanis the Omnipotent

{T}: Draw three cards.
{2}{U}{U}: Return Arcanis the Omnipotent to its owner's hand.

Overseer of the Damned

Flying
When Overseer of the Damned enters, you may destroy target creature.
Whenever a nontoken creature an opponent controls dies, create a tapped 2/2 black Zombie creature token.

Body Double

You may have Body Double enter as a copy of any creature card in a graveyard.

Charnel Serenade

Surveil 3, then return a creature card from your graveyard to the battlefield with a finality counter on it. Exile Charnel Serenade with three time counters on it.
Suspend 3—{2}{B} (Rather than cast this card from your hand, you may pay {2}{B} and exile it with three 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.)

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.)

Mulldrifter

Flying
When Mulldrifter enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

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.)

Lazav, the Multifarious

When Lazav, the Multifarious enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{X}: Lazav, the Multifarious becomes a copy of target creature card in your graveyard with mana value X, except its name is Lazav, the Multifarious, it's legendary in addition to its other types, and it has this ability.

Herald of Leshrac

Flying
Cumulative upkeep—Gain control of a land you don't control. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Herald of Leshrac gets +1/+1 for each land you control but don't own.
When Herald of Leshrac leaves the battlefield, each player gains control of each land they own that you control.

Clever Impersonator

You may have Clever Impersonator enter as a copy of any nonland permanent on the battlefield.

Black Sun's Zenith

Put X -1/-1 counters on each creature. Shuffle Black Sun's Zenith into its owner's library.

Ephara's Dispersal

This spell costs {2} less to cast if it targets an attacking creature.
Return target creature to its owner's hand. 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.)

Thief of Blood

Flying
As Thief of Blood enters, remove all counters from all permanents. Thief of Blood enters with a +1/+1 counter on it for each counter removed this way.

Mystic Sanctuary

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

Tocasia's Dig Site

{T}: Add {C}.
{3}, {T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Dream Eater

Flash
Flying
When Dream Eater enters, surveil 4. When you do, you may return target nonland permanent an opponent controls to its owner's hand. (To surveil 4, look at the top four cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Brainstorm

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

Unshakable Tail

When Unshakable Tail enters and at the beginning of your upkeep, surveil 1.
Whenever one or more creature cards are put into your graveyard from your library, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
{2}, Sacrifice a Clue: Return Unshakable Tail from your graveyard to your hand.

Hidden Grotto

When Hidden Grotto enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Case of the Shifting Visage

At the beginning of your upkeep, surveil 1.
To solve — There are fifteen or more cards in your graveyard. (If unsolved, solve at the beginning of your end step.)
Solved — Whenever you cast a nonlegendary creature spell, copy that spell. (The copy becomes a token.)

Ravenous Chupacabra

When Ravenous Chupacabra enters, destroy target creature an opponent controls.

Noosegraf Mob

Noosegraf Mob enters with five +1/+1 counters on it.
Whenever a player casts a spell, remove a +1/+1 counter from Noosegraf Mob. If you do, create a 2/2 black Zombie creature token.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Animate Dead

Enchant creature card in a graveyard
When Animate Dead enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Mindwhisker

At the beginning of your upkeep, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Threshold — As long as seven or more cards are in your graveyard, creatures your opponents control get -1/-0.

Master of Death

When Master of Death enters, 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.)
At the beginning of your upkeep, if Master of Death is in your graveyard, you may pay 1 life. If you do, return it to your hand.

Command Tower

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

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Watcher of Hours

Flying, ward {3}
Whenever you remove a time counter from Watcher of Hours while it's exiled, surveil 1.
Suspend 6—{1}{U} (Rather than cast this card from your hand, you may pay {1}{U} and exile it with six 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.)

Psychic Frog

Whenever Psychic Frog deals combat damage to a player or planeswalker, draw a card.
Discard a card: Put a +1/+1 counter on Psychic Frog.
Exile three cards from your graveyard: Psychic Frog gains flying until end of turn.

Island

Saw in Half

Destroy target creature. If that creature dies this way, its controller creates two tokens that are copies of that creature, except their power is half that creature's power and their toughness is half that creature's toughness. Round up each time.

Dimir Aqueduct

Dimir Aqueduct enters tapped.
When Dimir Aqueduct enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Twilight Prophet

Flying
Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
At the beginning of your upkeep, if you have the city's blessing, reveal the top card of your library and put it into your hand. Each opponent loses X life and you gain X life, where X is that card's mana value.

Tidespout Tyrant

Flying
Whenever you cast a spell, return target permanent to its owner's hand.