Eradicator Valkyrie

Flying, lifelink, hexproof from planeswalkers
Boast — {1}{B}, Sacrifice a creature: Each opponent sacrifices a creature or planeswalker. (Activate only if this creature attacked this turn and only once each turn.)

Seething Landscape

{T}: Add {C}.
{T}, Sacrifice Seething Landscape: Search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.
Cycling {U}{B}{R} ({U}{B}{R}, Discard this card: Draw a card.)

Swamp

Surreal Memoir

Return an instant card at random from your graveyard to your hand.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Enduring Courage

Whenever another creature you control enters, it gets +2/+0 and gains haste until end of turn.
When Enduring Courage dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Fear of Being Hunted

Haste
Fear of Being Hunted must be blocked if able.

Arcane Signet

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

Glimmerlight

When Glimmerlight enters, create a 1/1 white Glimmer enchantment creature token.
Equipped creature gets +1/+1.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Gingerbrute

Haste
{1}: Gingerbrute can't be blocked this turn except by creatures with haste.
{2}, {T}, Sacrifice Gingerbrute: You gain 3 life.

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Tormented Soul

Tormented Soul can't block and can't be blocked.

True-Name Nemesis

As True-Name Nemesis enters, choose a player.
True-Name Nemesis has protection from the chosen player.

Clammy Prowler

Whenever Clammy Prowler attacks, another target attacking creature can't be blocked this turn.

Kroxa, Titan of Death's Hunger

When Kroxa enters, sacrifice it unless it escaped.
Whenever Kroxa enters or attacks, each opponent discards a card, then each opponent who didn't discard a nonland card this way loses 3 life.
Escape—{B}{B}{R}{R}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Mountain

Baleful Strix

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

Goro-Goro and Satoru

Whenever one or more creatures you control that entered this turn deal combat damage to a player, create a 5/5 red Dragon Spirit creature token with flying.
{1}{R}: Creatures you control gain haste until end of turn.

Rakka Mar

Haste
{R}, {T}: Create a 3/1 red Elemental creature token with haste.

Island

Mist-Cloaked Herald

The Ancient One

Descend 8 — The Ancient One can't attack or block unless there are eight or more permanent cards in your graveyard.
{2}{U}{B}: Draw a card, then discard a card. When you discard a card this way, target player mills cards equal to its mana value.

Changeling Outcast

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

Enter the Enigma

Target creature can't be blocked this turn.
Draw a card.

Fear of Infinity

Flying, lifelink
Fear of Infinity can't block.
Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, you may return Fear of Infinity from your graveyard to your hand.

Silent Hallcreeper

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

Fear of Failed Tests

Whenever Fear of Failed Tests deals combat damage to a player, draw that many cards.

Treasure Nabber

Whenever an opponent taps an artifact for mana, gain control of that artifact until the end of your next turn.

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.)

Untimely Malfunction

Choose one —
• Destroy target artifact.
• Change the target of target spell or ability with a single target.
• One or two target creatures can't block this turn.

Appendage Amalgam

Flash
Whenever Appendage Amalgam attacks, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Devilish Valet

Trample, haste
Alliance — Whenever another creature you control enters, double Devilish Valet's power until end of turn.

Sol Ring

Utvara Hellkite

Flying
Whenever a Dragon you control attacks, create a 6/6 red Dragon creature token with flying.

Counterspell

Nowhere to Run

Flash
When Nowhere to Run enters, target creature an opponent controls gets -3/-3 until end of turn.
Creatures your opponents control can be the targets of spells and abilities as though they didn't have hexproof. Ward abilities of those creatures don't trigger.

Maestros Diabolist

Deathtouch, haste
Whenever Maestros Diabolist attacks, if you don't control a Devil token, create a tapped and attacking 1/1 red Devil creature token with "When this creature dies, it deals 1 damage to any target."

Ghostfire Slice

Devoid (This card has no color.)
This spell costs {2} less to cast if an opponent controls a multicolored permanent.
Ghostfire Slice deals 4 damage to any target.

Tetsuko Umezawa, Fugitive

Creatures you control with power or toughness 1 or less can't be blocked.

Dinosaur Headdress

When Dinosaur Headdress enters, attach it to target creature you control.
As Dinosaur Headdress becomes attached to a creature, choose an exiled creature card used to craft Dinosaur Headdress.
Equipped creature is a copy of the last chosen card.
Equip {2}

Paleontologist's Pick-Axe

Whenever equipped creature attacks, draw a card, then discard a card.
Equip {1}
Craft with one or more creatures {5} ({5}, Exile this artifact, Exile one or more creatures you control and/or creature cards from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Paleontologist's Pick-Axe // Dinosaur Headdress

Commander's Sphere

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

Widow's Walk

Whenever a creature you control attacks alone, it gets +1/+0 and gains deathtouch until end of turn.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Derelict Attic

When you unlock this door, you draw two cards and you lose 2 life.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Derelict Attic // Widow's Walk

Skinrender

When Skinrender enters, put three -1/-1 counters on target creature.

Reinforced Ronin

Haste
At the beginning of your end step, return Reinforced Ronin to its owner's hand.
Channel — {1}{R}, Discard Reinforced Ronin: Draw a card.

Norin, Swift Survivalist

Norin, Swift Survivalist can't block.
Whenever a creature you control becomes blocked, you may exile it. You may play that card from exile this turn.

Anger

Haste
As long as Anger is in your graveyard and you control a Mountain, creatures you control have haste.

Come Back Wrong

Destroy target creature. If a creature card is put into a graveyard this way, return it to the battlefield under your control. Sacrifice it at the beginning of your next end step.

Triton Shorestalker

Slither Blade

Consuming Corruption

Consuming Corruption deals X damage to target creature or planeswalker and you gain X life, where X is the number of Swamps you control.

Withering Torment

Destroy target creature or enchantment. You lose 2 life.

Fists of Flame

Draw a card. Until end of turn, target creature gains trample and gets +1/+0 for each card you've drawn this turn.

Loyal Apprentice

Haste
Lieutenant — At the beginning of combat on your turn, if you control your commander, create a 1/1 colorless Thopter artifact creature token with flying. That token gains haste until end of turn.

Urabrask's Forge

At the beginning of combat on your turn, put an oil counter on Urabrask's Forge, then create an X/1 red Phyrexian Horror creature token with trample and haste, where X is the number of oil counters on Urabrask's Forge. Sacrifice that token at the beginning of the next end step.

Yahenni, Undying Partisan

Haste
Whenever a creature an opponent controls dies, put a +1/+1 counter on Yahenni, Undying Partisan.
Sacrifice another creature: Yahenni gains indestructible until end of turn.

Darkslick Shores

Darkslick Shores enters tapped unless you control two or fewer other lands.
{T}: Add {U} or {B}.

Shoreline Looter

Shoreline Looter can't be blocked.
Threshold — Whenever Shoreline Looter deals combat damage to a player, draw a card. Then discard a card unless seven or more cards are in your graveyard.