Melira, Sylvok Outcast

You can't get poison counters.
Creatures you control can't have -1/-1 counters put on them.
Creatures your opponents control lose infect.

Devoted Druid

{T}: Add {G}.
Put a -1/-1 counter on Devoted Druid: Untap Devoted Druid.

Aether Vial

At the beginning of your upkeep, you may put a charge counter on Aether Vial.
{T}: You may put a creature card with mana value equal to the number of charge counters on Aether Vial from your hand onto the battlefield.

Noble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {G}, {W}, or {U}.

Forest

Temple Garden

({T}: Add {G} or {W}.)
As Temple Garden enters, you may pay 2 life. If you don't, it enters tapped.

Collected Company

Look at the top six cards of your library. Put up to two creature cards with mana value 3 or less from among them onto the battlefield. Put the rest on the bottom of your library in any order.

Vizier of Remedies

If one or more -1/-1 counters would be put on a creature you control, that many -1/-1 counters minus one are put on it instead.

Thalia, Guardian of Thraben

First strike
Noncreature spells cost {1} more to cast.

Chord of Calling

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Search your library for a creature card with mana value X or less, put it onto the battlefield, then shuffle.

Walking Ballista

Walking Ballista enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Quillspike

{B/G}, Remove a -1/-1 counter from a creature you control: Quillspike gets +3/+3 until end of turn.

Eladamri's Call

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

Plains

Windswept Heath

{T}, Pay 1 life, Sacrifice Windswept Heath: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Krallenhorde Howler

Creature spells you cast cost {1} less to cast.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Krallenhorde Howler.

Duskwatch Recruiter

{2}{G}: Look at the top three cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
At the beginning of each upkeep, if no spells were cast last turn, transform Duskwatch Recruiter.