Metalcraft — When Bleak Coven Vampires enters the battlefield, if you control three or more artifacts, target player loses 4 life and you gain 4 life.

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
: Regenerate Blight Mamba.

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
When Blistergrub dies, each opponent loses 2 life.

: Bloodshot Trainee deals 4 damage to target creature. Activate this ability only if Bloodshot Trainee's power is 4 or greater.

You gain 1 life for each creature on the battlefield. Prevent all combat damage that would be dealt this turn.

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature doesn't untap during its controller's untap step.

Metalcraft — Carapace Forger gets +2/+2 as long as you control three or more artifacts.

Flying
Carnifex Demon enters the battlefield with two -1/-1 counters on it.
, Remove a -1/-1 counter from Carnifex Demon: Put a -1/-1 counter on each other creature.

Create two 1/1 green Insect creature tokens with infect. (They deal damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Target opponent reveals the top card of their library. Cerebral Eruption deals damage equal to the revealed card's converted mana cost to that player and each creature that player controls. If a land card is revealed this way, return Cerebral Eruption to its owner's hand.

Chimeric Mass enters the battlefield with X charge counters on it.
: Until end of turn, Chimeric Mass becomes a Construct artifact creature with "This creature's power and toughness are each equal to the number of charge counters on it."

Metalcraft — Chrome Steed gets +2/+2 as long as you control three or more artifacts.

Imprint — When Clone Shell enters the battlefield, look at the top four cards of your library, exile one face down, then put the rest on the bottom of your library in any order.
When Clone Shell dies, turn the exiled card face up. If it's a creature card, put it onto the battlefield under your control.

When Contagion Clasp enters the battlefield, put a -1/-1 counter on target creature.
, : Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

When Contagion Engine enters the battlefield, put a -1/-1 counter on each creature target player controls.
, : Proliferate, then proliferate again. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

: Add .

Whenever Copperhorn Scout attacks, untap each other creature you control.

Copperline Gorge enters the battlefield tapped unless you control two or fewer other lands.
: Add or .

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Corpse Cur enters the battlefield, you may return target creature card with infect from your graveyard to your hand.