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

Black creature spells you cast cost {1} less to cast. Whenever you cast a creature spell, each opponent loses 1 life and you gain 1 life.

As this artifact enters, choose a creature type. Creature spells you cast of the chosen type cost {1} less to cast. At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Black spells you cast cost {1} less to cast.

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.) When this creature dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

This creature can't be blocked by Walls.

When this creature enters, each opponent discards a card.

Whenever this creature attacks or blocks, any player may exile a card from their graveyard. If a player does, this creature assigns no combat damage this turn.

When this creature dies, you may pay {B}. If you do, target player discards a card.

When this creature enters, target player mills two cards. When this creature dies, target creature you don't control gets -1/-1 until end of turn.

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.) Other Rats you control have toxic 1. When Karumonix enters, look at the top five cards of your library. You may reveal any number of Rat cards from among them and put the revealed cards into your hand. Put the rest on the bottom of your library in a random order.

This creature gets +1/+1 for each other creature on the battlefield named Relentless Rats. A deck can have any number of cards named Relentless Rats.

{B}, Pay 1 life: This creature gets +1/+0 until end of turn. Activate no more than three times each turn.

Shadow (This creature can block or be blocked by only creatures with shadow.) Whenever this creature deals combat damage to a player, each player discards a card.

As this enchantment enters, choose a creature type. Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

As an additional cost to cast this spell, sacrifice a creature. Draw two cards.

Destroy target creature with total power and toughness 5 or less.

Add {B}{B}{B}.

Target creature gets -1/-1 until end of turn for each Swamp you control.

Target opponent loses 1 life for each attacking creature you control. You gain that much life.

Destroy target nonartifact creature.

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.

{2}, {T}: Add {B} for each Swamp you control.

({T}: Add {B}.)

{T}: Add {C}. {T}: Regenerate target Insect, Rat, Spider, or Squirrel. (The next time it would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

As The Black Gate enters, you may pay 3 life. If you don't, it enters tapped. {T}: Add {B}. {1}{B}, {T}: Choose a player with the most life or tied for most life. Target creature can't be blocked by creatures that player controls this turn.

Search your library for a card, put that card into your hand, then shuffle.

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.