Whenever a black card is put into an opponent's graveyard from anywhere, you may draw a card.

As an additional cost to cast this spell, sacrifice a creature.
Creatures you control gain indestructible until end of turn. Put a +1/+1 counter on each creature you control. (Damage and effects that say "destroy" don't destroy those creatures.)

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

, : Add .

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

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

This spell can't be countered. (This includes by the ward ability.)
Destroy target creature or planeswalker with mana value 3 or less.

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

Each opponent can't cast noncreature spells with mana value greater than the number of lands that player controls.
Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell.

Equipped creature gets +1/+1 for each color among permanents you control.
As long as this Equipment is attached to a creature, your opponents can't cast spells during your turn.
Equip

Spree (Choose one or more additional costs.)
+ — Copy target instant spell, sorcery spell, activated ability, or triggered ability. You may choose new targets for the copy.
+ — Change the target of target spell or ability with a single target.

Choose target spell or permanent that's red or green. Its owner puts it on their choice of the top or bottom of their library.

: Return this card from your graveyard to the battlefield tapped.

Shadow (This creature can block or be blocked by only creatures with shadow.)
If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.
, Sacrifice this creature: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Grapeshot deals 1 damage to any target.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Sliver creatures you control have flying and haste.

Whenever an Aura you control enters, if you cast it, you may search your library for an Aura card with mana value less than or equal to that Aura and with a different name than each Aura you control, put that card onto the battlefield attached to Light-Paws, then shuffle.

Whenever an opponent casts a spell during your turn and when this creature dies, create a green and white Elemental creature token with "This token's power and toughness are each equal to the number of creatures you control."

Return up to X target artifact and/or non-Aura enchantment cards each with mana value X or less from your graveyard to the battlefield. If X is 6 or more, those permanents are 4/4 creatures in addition to their other types.

Proliferate, then choose any number of permanents you control that had a counter put on them this way. Those permanents phase out. (To proliferate, choose any number of permanents and/or players, then give each another counter of each kind already there. Treat phased-out permanents and anything attached to them as though they don't exist until their controller's next turn.)

At the beginning of each player's draw step, that player draws an additional card.

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

Enchant creature card in a graveyard
When this Aura enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with this Aura." Return enchanted creature card to the battlefield under your control and attach this Aura to it. When this Aura leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

You may have this creature enter as a copy of any creature on the battlefield, except it's an Illusion in addition to its other types and it has "When this creature becomes the target of a spell or ability, sacrifice it."

Flash
Whenever an opponent searches their library, you gain 1 life and draw a card.

Lands you control are every basic land type in addition to their other types.

All Slivers have "Pay 2 life: Return this permanent to its owner's hand."

Each player chooses a number of lands they control equal to the number of lands controlled by the player who controls the fewest, then sacrifices the rest. Players discard cards and sacrifice creatures the same way.

Choose a card name, then target player mills a card. If a card with the chosen name was milled this way, you draw two cards. Otherwise, you draw a card.

Whenever a commander you control deals combat damage to an opponent, it deals that much damage to each other opponent.
Partner (You can have two commanders if both have partner.)

When you cast this spell, you gain half X life and draw half X cards. Round down each time.
Flying, trample
This creature enters with X +1/+1 counters on it.

, : Add .

: Exile target card from a graveyard. If it was a creature card, put a +1/+1 counter on this creature and you gain 1 life.

Lightning Strike deals 3 damage to any target.

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

When this creature enters, you may search your library for an Equipment card, reveal it, put it into your hand, then shuffle.
, : You may put an Equipment card from your hand onto the battlefield.