Swarm of Rats

Swarm of Rats's power is equal to the number of Rats you control.

Ashnod's Altar

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Wayfarer's Bauble

{2}, {T}, Sacrifice this artifact: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if there are seven or more cards in your graveyard.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Infectious Inquiry

You draw two cards and you lose 2 life. Each opponent gets a poison counter.

Sign in Blood

Target player draws two cards and loses 2 life.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Defile

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

Murder

Arcane Signet

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

Swamp

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

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.

Dark Ritual

Commander's Sphere

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

Night's Whisper

Village Rites

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

Unearth

Return target creature card with mana value 3 or less from your graveyard to the battlefield.
Cycling {2} ({2}, Discard this card: Draw a card.)

Leaden Myr

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Doom Blade

Haunted Cloak

Equipped creature has vigilance, trample, and haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Ornithopter of Paradise

Rat Colony

This creature gets +1/+0 for each other Rat you control.
A deck can have any number of cards named Rat Colony.