Bleed Dry

Target creature gets -13/-13 until end of turn. If that creature would die this turn, exile it instead.

Demonic Bargain

Exile the top thirteen cards of your library, then search your library for a card. Put that card into your hand, then shuffle.

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.)

Dance with Calamity

Shuffle your library. As many times as you choose, you may exile the top card of your library. If the total mana value of the cards exiled this way is 13 or less, you may cast any number of spells from among those cards without paying their mana costs.

Commander's Sphere

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

Army of the Damned

Create thirteen tapped 2/2 black Zombie creature tokens.
Flashback {7}{B}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Dimir Signet

Tragic Fall

Target creature gets -3/-3 until end of turn.
Hellbent — That creature gets -13/-13 until end of turn instead if you have no cards in hand.

Relic of Sauron

{T}: Add two mana in any combination of {U}, {B}, and/or {R}.
{3}, {T}: Draw two cards, then discard a card.

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Big Score

As an additional cost to cast this spell, discard a card.
Draw two cards and create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Blasphemous Edict

You may pay {B} rather than pay this spell's mana cost if there are thirteen or more creatures on the battlefield.
Each player sacrifices thirteen creatures of their choice.

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Triskaidekaphobia

At the beginning of your upkeep, choose one —
• Each player with exactly 13 life loses the game, then each player gains 1 life.
• Each player with exactly 13 life loses the game, then each player loses 1 life.

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. This artifact deals 1 damage to you.

Howling Mine

At the beginning of each player's draw step, if this artifact is untapped, that player draws an additional card.

Sunbird's Invocation

Whenever you cast a spell from your hand, reveal the top X cards of your library, where X is that spell's mana value. You may cast a spell with mana value X or less from among cards revealed this way without paying its mana cost. Put the rest on the bottom of your library in a random order.

Deluge of the Dead

When this enchantment enters, create two 2/2 black Zombie creature tokens.
{2}{B}: Exile target card from a graveyard. If it was a creature card, create a 2/2 black Zombie creature token.

Invasion of Innistrad

(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.)
Flash
When this Siege enters, target creature an opponent controls gets -13/-13 until end of turn.

Invasion of Innistrad // Deluge of the Dead

Vial Smasher the Fierce

Whenever you cast your first spell each turn, choose an opponent at random. Vial Smasher deals damage equal to that spell's mana value to that player or a planeswalker that player controls.
Partner (You can have two commanders if both have partner.)

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Rakdos Signet

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Sol Ring

Razortrap Gorge

This land enters tapped unless a player has 13 or less life.
{T}: Add {B} or {R}.

Triskaidekaphile

You have no maximum hand size.
At the beginning of your upkeep, if you have exactly thirteen cards in your hand, you win the game.
{3}{U}: Draw a card.

Negate

Peculiar Lighthouse

This land enters tapped unless a player has 13 or less life.
{T}: Add {U} or {R}.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. This artifact deals 1 damage to you.

Arcane Signet

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

Izzet Signet

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Night's Whisper

Ludevic, Necro-Alchemist

At the beginning of each player's end step, that player may draw a card if a player other than you lost life this turn.
Partner (You can have two commanders if both have partner.)

Sorin the Mirthless

+1: Look at the top card of your library. You may reveal that card and put it into your hand. If you do, you lose life equal to its mana value.
−2: Create a 2/3 black Vampire creature token with flying and lifelink.
−7: Sorin deals 13 damage to any target. You gain 13 life.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Murky Sewer

This land enters tapped unless a player has 13 or less life.
{T}: Add {U} or {B}.

Counterspell

Unexpected Windfall

Terminate

Destroy target creature. It can't be regenerated.

Withengar Unbound

Flying, intimidate, trample (A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a player loses the game, put thirteen +1/+1 counters on Withengar Unbound.

Elbrus, the Binding Blade

Equipped creature gets +1/+0.
When equipped creature deals combat damage to a player, unattach Elbrus, then transform it.
Equip {1}

Elbrus, the Binding Blade // Withengar Unbound

Nightscape Familiar

Blue spells and red spells you cast cost {1} less to cast.
{1}{B}: Regenerate this creature.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Stensia Uprising

At the beginning of your end step, create a 1/1 red Human creature token. Then if you control exactly thirteen permanents, you may sacrifice this enchantment. When you do, it deals 7 damage to any target.