Consider

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

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Blessed Respite

Target player shuffles their graveyard into their library. Prevent all combat damage that would be dealt this turn.

Ardenvale Fealty

Create a 2/2 white Knight creature token with vigilance. (Then exile this card. You may cast the enchantment later from exile.)

Virtue of Loyalty

At the beginning of your end step, put a +1/+1 counter on each creature you control. Untap those creatures.

Virtue of Loyalty // Ardenvale Fealty

Vantress Visions

Copy target activated or triggered ability you control. You may choose new targets for the copy.

Virtue of Knowledge

If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Virtue of Knowledge // Vantress Visions

Cliffhaven Vampire

Flying
Whenever you gain life, each opponent loses 1 life.

Neva, Stalked by Nightmares

Menace
When Neva, Stalked by Nightmares enters the battlefield, return target creature or enchantment card from your graveyard to your hand.
Whenever an enchantment you control is put into a graveyard from the battlefield, put a +1/+1 counter on Neva, then scry 1.

Umara Entangler

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

Angelic Captain

Flying
Whenever Angelic Captain attacks, it gets +1/+1 until end of turn for each other attacking Ally.

Vivien on the Hunt

+2: You may sacrifice a creature. If you do, search your library for a creature card with mana value equal to 1 plus the sacrificed creature's mana value, put it onto the battlefield, then shuffle.
+1: Mill five cards, then put any number of creature cards milled this way into your hand.
−1: Create a 4/4 green Rhino Warrior creature token.

Rogues' Gallery

For each color, return up to one target creature card of that color from your graveyard to your hand.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Jiang Yanggu, Wildcrafter

Each creature you control with a +1/+1 counter on it has "{T}: Add one mana of any color."
−1: Put a +1/+1 counter on target creature.

Agadeem Occultist

{T}: Put target creature card from an opponent's graveyard onto the battlefield under your control if its mana value is less than or equal to the number of Allies you control.

Kazuul Warlord

Whenever Kazuul Warlord or another Ally enters the battlefield under your control, you may put a +1/+1 counter on each Ally creature you control.

Deal Gone Bad

Target creature gets -3/-3 until end of turn. Target player mills three cards. (They put the top three cards of their library into their graveyard.)

Circular Logic

Counter target spell unless its controller pays {1} for each card in your graveyard.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Firemantle Mage

Rally — Whenever Firemantle Mage or another Ally enters the battlefield under your control, creatures you control gain menace until end of turn. (A creature with menace can't be blocked except by two or more creatures.)

Mountain

Abundance

If you would draw a card, you may instead choose land or nonland and reveal cards from the top of your library until you reveal a card of the chosen kind. Put that card into your hand and put all other cards revealed this way on the bottom of your library in any order.

Always Watching

Nontoken creatures you control get +1/+1 and have vigilance.

Bonders' Enclave

{T}: Add {C}.
{3}, {T}: Draw a card. Activate only if you control a creature with power 4 or greater.

Forest

Sea Gate Loremaster

{T}: Draw a card for each Ally you control.

Skyrider Elf

Flying
Converge — Skyrider Elf enters the battlefield with a +1/+1 counter on it for each color of mana spent to cast it.

Diabolic Edict

Brokers Charm

Choose one —
• Target creature you control gets +1/+0 until end of turn. It deals damage equal to its power to target creature or planeswalker an opponent controls.
• Destroy target enchantment.
• Draw two cards.

Munda, Ambush Leader

Haste
Rally — Whenever Munda, Ambush Leader or another Ally enters the battlefield under your control, you may look at the top four cards of your library. If you do, reveal any number of Ally cards from among them, then put those cards on top of your library in any order and the rest on the bottom in any order.

Island

Shatterskull Recruit

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

Drana, Liberator of Malakir

Flying, first strike
Whenever Drana, Liberator of Malakir deals combat damage to a player, put a +1/+1 counter on each attacking creature you control.

The Autonomous Furnace

The Autonomous Furnace enters the battlefield tapped.
{T}: Add {R}.
{1}{R}, {T}, Sacrifice The Autonomous Furnace: Draw a card.

Drana's Emissary

Flying
At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Mina and Denn, Wildborn

You may play an additional land on each of your turns.
{R}{G}, Return a land you control to its owner's hand: Target creature gains trample until end of turn.

Adventurous Impulse

Look at the top three cards of your library. You may reveal a creature or land card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Colossal Majesty

At the beginning of your upkeep, if you control a creature with power 4 or greater, draw a card.

The Fair Basilica

The Fair Basilica enters the battlefield tapped.
{T}: Add {W}.
{1}{W}, {T}, Sacrifice The Fair Basilica: Draw a card.

Unnatural Growth

At the beginning of each combat, double the power and toughness of each creature you control until end of turn.

Locthwain Scorn

Target creature gets -3/-3 until end of turn. You gain 2 life.

Virtue of Persistence

At the beginning of your upkeep, put target creature card from a graveyard onto the battlefield under your control.

Virtue of Persistence // Locthwain Scorn

Spore Frog

Sacrifice Spore Frog: Prevent all combat damage that would be dealt this turn.

Tear Asunder

Kicker {1}{B} (You may pay an additional {1}{B} as you cast this spell.)
Exile target artifact or enchantment. If this spell was kicked, exile target nonland permanent instead.

Pilgrim's Eye

Flying
When Pilgrim's Eye enters the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Swamp

Angel of Renewal

Flying
When Angel of Renewal enters the battlefield, you gain 1 life for each creature you control.

Panharmonicon

If an artifact or creature entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

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 the battlefield 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.

Vindicate

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Veteran Warleader

Veteran Warleader's power and toughness are each equal to the number of creatures you control.
Tap another untapped Ally you control: Veteran Warleader gains your choice of first strike, vigilance, or trample until end of turn.

Expand the Sphere

Look at the top six cards of your library. Put up to two land cards from among them onto the battlefield tapped and the rest on the bottom of your library in a random order. If you put fewer than two lands onto the battlefield this way, proliferate a number of times equal to the difference. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Social Climber

Alliance — Whenever another creature enters the battlefield under your control, you gain 1 life.

Joraga Auxiliary

{4}{G}{W}: Support 2. (Put a +1/+1 counter on each of up to two other target creatures.)

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Saint Traft and Rem Karolus

Whenever Saint Traft and Rem Karolus becomes tapped, create a 1/1 red Human creature token if this is the first time this ability has resolved this turn. If it's the second time, create a 1/1 blue Spirit creature token with flying. If it's the third time, create a 4/4 white Angel creature token with flying.
Whenever you cast a spell that has convoke, untap Saint Traft and Rem Karolus.

Glorious Anthem

The Surgical Bay

The Surgical Bay enters the battlefield tapped.
{T}: Add {U}.
{1}{U}, {T}, Sacrifice The Surgical Bay: Draw a card.

Cleanup Crew

When Cleanup Crew enters the battlefield, choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.
• You gain 4 life.

Threats Undetected

Search your library for up to four creature cards with different powers and reveal them. An opponent chooses two of those cards. Shuffle the chosen cards into your library and put the rest into your hand.

The Dross Pits

The Dross Pits enters the battlefield tapped.
{T}: Add {B}.
{1}{B}, {T}, Sacrifice The Dross Pits: Draw a card.

Plains

General Tazri

When General Tazri enters the battlefield, you may search your library for an Ally creature card, reveal it, put it into your hand, then shuffle.
{W}{U}{B}{R}{G}: Ally creatures you control get +X/+X until end of turn, where X is the number of colors among those creatures.

Cave of Temptation

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{4}, {T}, Sacrifice Cave of Temptation: Put two +1/+1 counters on target creature. Activate only as a sorcery.

Call to the Kindred

Enchant creature
At the beginning of your upkeep, you may look at the top five cards of your library. If you do, you may put a creature card that shares a creature type with enchanted creature from among them onto the battlefield, then you put the rest of those cards on the bottom of your library in any order.

Beastcaller Savant

Haste
{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Mortality Spear

This spell costs {2} less to cast if you gained life this turn.
Destroy target nonland permanent.

Return from the Wilds

Choose two —
• Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
• Create a 1/1 white Human creature token.
• Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Urza's Rebuff

Choose one —
• Counter target spell.
• Tap up to two target creatures.

Harabaz Druid

{T}: Add X mana of any one color, where X is the number of Allies you control.

Ally Encampment

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast an Ally spell.
{1}, {T}, Sacrifice Ally Encampment: Return target Ally you control to its owner's hand.

Marshal's Anthem

Multikicker {1}{W} (You may pay an additional {1}{W} any number of times as you cast this spell.)
Creatures you control get +1/+1.
When Marshal's Anthem enters the battlefield, return up to X target creature cards from your graveyard to the battlefield, where X is the number of times Marshal's Anthem was kicked.

Vampire Envoy

Flying
Whenever Vampire Envoy becomes tapped, you gain 1 life.

Bloodbond Vampire

Whenever you gain life, put a +1/+1 counter on Bloodbond Vampire.

Chasm Guide

Rally — Whenever Chasm Guide or another Ally enters the battlefield under your control, creatures you control gain haste until end of turn.

The Hunter Maze

The Hunter Maze enters the battlefield tapped.
{T}: Add {G}.
{1}{G}, {T}, Sacrifice The Hunter Maze: Draw a card.

Caetus, Sea Tyrant of Segovia

Noncreature spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a noncreature spell pays for {1} or one mana of that creature's color.)
At the beginning of your end step, untap up to four target creatures.

Invasion of Segovia

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Segovia enters the battlefield, create two 1/1 blue Kraken creature tokens with trample.