Cast Down

Island

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Lórien Revealed

Draw three cards.
Islandcycling {1} ({1}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
This creature can't be blocked.

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Contaminated Aquifer

({T}: Add {U} or {B}.)
This land enters tapped.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Swamp

Counterspell

Infectious Inquiry

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

Pestilent Syphoner

Flying
Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)

Thrummingbird

Flying
Whenever this creature deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)