Lulu, Stern Guardian

Whenever an opponent attacks you, choose target creature attacking you. Put a stun counter on that creature.
{3}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Ellie and Alan, Paleontologists

{T}, Exile a creature card from your graveyard: Discover X, where X is the mana value of the exiled card. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with that mana value or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Medicine Runner

When this creature enters, you may remove a counter from target permanent.

Founding the Third Path

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — You may cast an instant or sorcery spell with mana value 1 or 2 from your hand without paying its mana cost.
II — Target player mills four cards.
III — Exile target instant or sorcery card from your graveyard. Copy it. You may cast the copy.

Island

Kishla Village

This land enters tapped unless you control an Island or a Swamp.
{T}: Add {G}.
{3}{G}, {T}: 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.)

Veiled Ascension

When this enchantment enters, put a flying counter on each face-down creature you control.
Face-down creatures you control enter with a flying counter on them.
At the beginning of your upkeep, you may cloak the top card of your library.

Patchwork Beastie

Delirium — This creature can't attack or block unless there are four or more card types among cards in your graveyard.
At the beginning of your upkeep, you may mill a card. (You may put the top card of your library into your graveyard.)

Distinguished Conjurer

Whenever another creature you control enters, you gain 1 life.
{4}{W}, {T}: Exile another target creature you control, then return it to the battlefield under its owner's control.

Thijarian Witness

Flash
Bear Witness — Whenever another creature dies, if it was attacking or blocking alone, exile it and investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Mastery of the Unseen

Whenever a permanent you control is turned face up, you gain 1 life for each creature you control.
{3}{W}: Manifest the top card of your library. (Put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Found Footage

You may look at face-down creatures your opponents control any time.
{2}, Sacrifice this artifact: 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.)

The Seriema

When The Seriema enters, search your library for a legendary creature card, reveal it, put it into your hand, then shuffle.
Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery. It's an artifact creature at 7+.)
STATION 7+
Flying
Other tapped legendary creatures you control have indestructible.

Proper Burial

Whenever a creature you control dies, you gain life equal to that creature's toughness.

Plains

Twitch

You may tap or untap target artifact, creature, or land.
Draw a card.

Mage's Attendant

When this creature enters, create a 1/1 blue Wizard creature token with "{1}, Sacrifice this token: Counter target noncreature spell unless its controller pays {1}."

Ambling Stormshell

Ward {2}
Whenever this creature attacks, put three stun counters on it and draw three cards. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Whenever you cast a Turtle spell, untap this creature.

Galadriel, Light of Valinor

Alliance — Whenever another creature you control enters, choose one that hasn't been chosen this turn —
• Add {G}{G}{G}.
• Put a +1/+1 counter on each creature you control.
• Scry 2, then draw a card.

River Kelpie

Whenever this creature or another permanent enters from a graveyard, draw a card.
Whenever a player casts a spell from a graveyard, draw a card.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Traverse the Ulvenwald

Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Delirium — If there are four or more card types among cards in your graveyard, instead search your library for a creature or land card, reveal it, put it into your hand, then shuffle.

Ioreth of the Healing House

{T}: Untap another target permanent.
{T}: Untap two other target legendary creatures.

Shield-Wall Sentinel

Defender
When this creature enters, you may search your library for a creature card with defender, reveal it, put it into your hand, then shuffle.

Forest

Forensic Researcher

{T}: Untap another target permanent you control.
{T}, Collect evidence 3: Tap target creature you don't control. (To collect evidence 3, exile cards with total mana value 3 or greater from your graveyard.)

Dredger's Insight

Whenever one or more artifact and/or creature cards leave your graveyard, you gain 1 life.
When this enchantment enters, mill four cards. You may put an artifact, creature, or land card from among the milled cards into your hand. (To mill four cards, put the top four cards of your library into your graveyard.)

Three Tree Mascot

Changeling (This card is every creature type.)
{1}: Add one mana of any color. Activate only once each turn.

Summon: Esper Maduin

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Reveal the top card of your library. If it's a permanent card, put it into your hand.
II — Add {G}{G}.
III — Other creatures you control get +2/+2 and gain trample until end of turn.

Esper Origins

Surveil 2. You gain 2 life. If this spell was cast from a graveyard, exile it, then put it onto the battlefield transformed under its owner's control with a finality counter on it. (If a creature with a finality counter on it would die, exile it instead.)
Flashback {3}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Esper Origins // Summon: Esper Maduin

Blink

Sheltered by Ghosts

Enchant creature you control
When this Aura enters, exile target nonland permanent an opponent controls until this Aura leaves the battlefield.
Enchanted creature gets +1/+0 and has lifelink and ward {2}.

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 this Siege enters, create two 1/1 blue Kraken creature tokens with trample.

Invasion of Segovia // Caetus, Sea Tyrant of Segovia

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Mountain

Orb of Dreams

Obscuring Aether

Face-down creature spells you cast cost {1} less to cast.
{1}{G}: Turn this enchantment face down. (It becomes a 2/2 creature.)

Solitary Sanctuary

When this enchantment enters, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Whenever you tap an untapped creature an opponent controls, put a +1/+1 counter on target creature you control.

Tunnel Tipster

At the beginning of your end step, if a face-down creature entered the battlefield under your control this turn, put a +1/+1 counter on this creature.
{T}: Add {G}.

Wakestone Gargoyle

Defender, flying
{1}{W}: Creatures you control with defender can attack this turn as though they didn't have defender.

Unyielding Gatekeeper

Disguise {1}{W} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When this creature is turned face up, exile another target nonland permanent. If you controlled it, return it to the battlefield tapped. Otherwise, its controller creates a 2/2 white and blue Detective creature token.

Izzet Boilerworks

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

Loot, the Pathfinder

Double strike, vigilance, haste
Exhaust — {G}, {T}: Add three mana of any one color. (Activate each exhaust ability only once.)
Exhaust — {U}, {T}: Draw three cards.
Exhaust — {R}, {T}: Loot deals 3 damage to any target.

Winternight Stories

Draw three cards. Then discard two cards unless you discard a creature card.
Harmonize {4}{U} (You may cast this card from your graveyard for its harmonize cost. You may tap a creature you control to reduce that cost by {X}, where X is its power. Then exile this spell.)

Rancor

Enchant creature
Enchanted creature gets +2/+0 and has trample.
When this Aura is put into a graveyard from the battlefield, return it to its owner's hand.

Den Protector

Creatures with power less than this creature's power can't block it.
Megamorph {1}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When this creature is turned face up, return target card from your graveyard to your hand.

Insidious Fungus

{2}, Sacrifice this creature: Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Draw a card. Then you may put a land card from your hand onto the battlefield tapped.

Zygon Infiltrator

Body-print — {2}{U}: Tap another target creature and put a stun counter on it. This creature becomes a copy of that creature for as long as that creature remains tapped. Activate only as a sorcery. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Wingmantle Chaplain

Defender
When this creature enters, create a 1/1 white Bird creature token with flying for each creature with defender you control.
Whenever another creature you control with defender enters, create a 1/1 white Bird creature token with flying.

Investigator's Journal

This artifact enters with a number of suspect counters on it equal to the greatest number of creatures a player controls.
{2}, {T}, Remove a suspect counter from this artifact: Draw a card.
{2}, Sacrifice this artifact: Draw a card.

Sleep-Cursed Faerie

Flying, ward {2}
This creature enters tapped with three stun counters on it. (If it would become untapped, remove a stun counter from it instead.)
{1}{U}: Untap this creature.