Cazur, Ruthless Stalker

Partner with Ukkima, Stalking Shadow (When this creature enters, target player may put Ukkima into their hand from their library, then shuffle.)
Whenever a creature you control deals combat damage to a player, put a +1/+1 counter on that creature.

Dimir Infiltrator

This creature can't be blocked.
Transmute {1}{U}{B} ({1}{U}{B}, 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.)

Flitterstep Eidolon

Bestow {5}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
This creature can't be blocked.
Enchanted creature gets +1/+1 and can't be blocked.

Basim Ibn Ishaq

Whenever you cast a historic spell, draw a card. Basim Ibn Ishaq can't be blocked this turn. This ability triggers only once each turn. (Artifacts, legendaries, and Sagas are historic.)
Whenever Basim Ibn Ishaq deals combat damage to a player, put a +1/+1 counter on it.

Amphibian Downpour

Flash
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies. Copies become tokens.)
Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1.

Guild Thief

Whenever this creature deals combat damage to a player, put a +1/+1 counter on it.
Cunning Action — {3}{U}: This creature can't be blocked this turn.

Aether Tunnel

Enchant creature
Enchanted creature gets +1/+0 and can't be blocked.

Etched Slith

Menace
Whenever this creature deals combat damage to a player, put a +1/+1 counter on it. When you do, you may remove a counter from another target permanent or opponent.

Ukkima, Stalking Shadow

Partner with Cazur, Ruthless Stalker (When this creature enters, target player may put Cazur into their hand from their library, then shuffle.)
Ukkima can't be blocked.
When Ukkima leaves the battlefield, it deals X damage to target player and you gain X life, where X is its power.

Gudul Lurker

This creature can't be blocked.
Megamorph {U} (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.)

Cloak of Mists

Enchant creature
Enchanted creature can't be blocked.

Kenrith's Transformation

Enchant creature
When this Aura enters, draw a card.
Enchanted creature loses all abilities and is a green Elk creature with base power and toughness 3/3. (It loses all other card types and creature types.)

Triton Shorestalker

Dryad Sophisticate

Nonbasic landwalk (This creature can't be blocked as long as defending player controls a nonbasic land.)

Trygon Predator

Flying
Whenever this creature deals combat damage to a player, you may destroy target artifact or enchantment that player controls.

Go for the Throat

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Jhessian Infiltrator

Utter Insignificance

Flash
Enchant creature
Enchanted creature loses all abilities and has base power and toughness 1/1.
{2}{C}: Exile enchanted creature.

Inkfathom Infiltrator

This creature can't block and can't be blocked.

Skullbriar, the Walking Grave

Haste
Whenever Skullbriar deals combat damage to a player, put a +1/+1 counter on it.
Counters remain on Skullbriar as it moves to any zone other than a player's hand or library.

Escape Artist

This creature can't be blocked.
{U}, Discard a card: Return this creature to its owner's hand.

Unable to Scream

Enchant creature
Enchanted creature loses all abilities and is a Toy artifact creature with base power and toughness 0/2 in addition to its other types.
As long as enchanted creature is face down, it can't be turned face up.

Prickly Boggart

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Fell

Reclamation Sage

When this creature enters, you may destroy target artifact or enchantment.

Forest

Llanowar Reborn

This land enters tapped.
{T}: Add {G}.
Graft 1 (This land enters with a +1/+1 counter on it. Whenever a creature enters, you may move a +1/+1 counter from this land onto it.)

Aether Figment

Kicker {3} (You may pay an additional {3} as you cast this spell.)
If this creature was kicked, it enters with two +1/+1 counters on it.
This creature can't be blocked.

Dauthi Horror

Shadow (This creature can block or be blocked by only creatures with shadow.)
This creature can't be blocked by white creatures.

Over the Edge

Choose one —
• Destroy target artifact or enchantment.
• Target creature you control explores, then it explores again. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then put the card back or put it into your graveyard. Then repeat this process.)

Tamiyo's Compleation

Flash
Enchant artifact, creature, or planeswalker
When this Aura enters, tap enchanted permanent. If it's an Equipment, unattach it.
Enchanted permanent loses all abilities and doesn't untap during its controller's untap step.

Changeling Outcast

Changeling (This card is every creature type.)
This creature can't block and can't be blocked.

Maelstrom Pulse

Destroy target nonland permanent and all other permanents with the same name as that permanent.

Swamp

Command Tower

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

Ichthyomorphosis

Enchant creature
Enchanted creature loses all abilities and is a blue Fish with base power and toughness 0/1.

Invisible Stalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
This creature can't be blocked.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Slither Blade

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Path of Ancestry

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Power Word Kill

Destroy target non-Angel, non-Demon, non-Devil, non-Dragon creature.

Silent Hallcreeper

This creature can't be blocked.
Whenever this creature deals combat damage to a player, choose one that hasn't been chosen —
• Put two +1/+1 counters on this creature.
• Draw a card.
• This creature becomes a copy of another target creature you control.

Metathran Soldier

Bred for the Hunt

Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, you may draw a card.

Stop Cold

Flash
Enchant artifact or creature
When this Aura enters, tap enchanted permanent.
Enchanted permanent loses all abilities and doesn't untap during its controller's untap step.

Eaten by Piranhas

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature loses all abilities and is a black Skeleton creature with base power and toughness 1/1. (It loses all other colors, card types, and creature types.)

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
This creature can't be blocked.

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

River Sneak

This creature can't be blocked.
Whenever another Merfolk you control enters, this creature gets +1/+1 until end of turn.

Cast Down

Tormented Soul

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Frogify

Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1. (It loses all other card types and creature types.)

Vedalken Infiltrator

This creature can't be blocked.
Metalcraft — This creature gets +1/+0 as long as you control three or more artifacts.

Power Fist

Equipped creature has trample and "Whenever this creature deals combat damage to a player, put that many +1/+1 counters on it."
Equip {2}

Sultai Charm

Choose one —
• Destroy target monocolored creature.
• Destroy target artifact or enchantment.
• Draw two cards, then discard a card.

Kasmina's Transmutation

Enchant creature
Enchanted creature loses all abilities and has base power and toughness 1/1.

Cold-Eyed Selkie

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever this creature deals combat damage to a player, you may draw that many cards.

Mist-Cloaked Herald

Hero's Demise

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Island

Silhana Ledgewalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
This creature can't be blocked except by creatures with flying.

Faerie Bladecrafter

Flying
Whenever one or more Faeries you control deal combat damage to a player, put a +1/+1 counter on this creature.
When this creature dies, each opponent loses X life and you gain X life, where X is its power.

Lignify

Enchant creature
Enchanted creature is a Treefolk with base power and toughness 0/4 and loses all abilities.

Thrummingbird

Flying
Whenever this creature deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)