Archivist of Oghma

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

Outrider en-Kor

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
{0}: The next 1 damage that would be dealt to Outrider en-Kor this turn is dealt to target creature you control instead.

Mentor of the Meek

Whenever another creature with power 2 or less enters the battlefield under your control, you may pay {1}. If you do, draw a card.

Changeling Hero

Changeling (This card is every creature type.)
Champion a creature (When this enters the battlefield, sacrifice it unless you exile another creature you control. When this leaves the battlefield, that card returns to the battlefield.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Children of Korlis

Sacrifice Children of Korlis: You gain life equal to the life you've lost this turn. (Damage causes loss of life.)

Zealot il-Vec

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Zealot il-Vec attacks and isn't blocked, you may have it deal 1 damage to target creature. If you do, prevent all combat damage Zealot il-Vec would deal this turn.

Rumor Gatherer

Alliance — Whenever another creature enters the battlefield under your control, scry 1. If this is the second time this ability has resolved this turn, draw a card instead.

Task Force

Whenever Task Force becomes the target of a spell or ability, it gets +0/+3 until end of turn.

Lin Sivvi, Defiant Hero

{X}, {T}: Search your library for a Rebel permanent card with mana value X or less, put it onto the battlefield, then shuffle.
{3}: Put target Rebel card from your graveyard on the bottom of your library.

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Drumbellower

Flying
Untap all creatures you control during each other player's untap step.

Avian Changeling

Changeling (This card is every creature type.)
Flying

Keeper of the Accord

At the beginning of each opponent's end step, if that player controls more creatures than you, create a 1/1 white Soldier creature token.
At the beginning of each opponent's end step, if that player controls more lands than you, you may search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Welcoming Vampire

Flying
Whenever one or more other creatures with power 2 or less enter the battlefield under your control, draw a card. This ability triggers only once each turn.

Ballista Squad

{X}{W}, {T}: Ballista Squad deals X damage to target attacking or blocking creature.

Aven Mindcensor

Flash
Flying
If an opponent would search a library, that player searches the top four cards of that library instead.

Riftmarked Knight

Protection from black; flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
Suspend 3—{1}{W}{W}
When the last time counter is removed from Riftmarked Knight while it's exiled, create a 2/2 black Knight creature token with flanking, protection from white, and haste.

Reveille Squad

Whenever one or more creatures attack you, if Reveille Squad is untapped, you may untap all creatures you control.

Irregular Cohort

Changeling (This card is every creature type.)
When Irregular Cohort enters the battlefield, create a 2/2 colorless Shapeshifter creature token with changeling.

Bound in Silence

Enchant creature
Enchanted creature can't attack or block.

Cho-Manno, Revolutionary

Prevent all damage that would be dealt to Cho-Manno, Revolutionary.

Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters the battlefield, choose a creature type.
Whenever another creature of the chosen type enters the battlefield under your control, put a +1/+1 counter on Bloodline Pretender.

Phyrexian Censor

Each player can't cast more than one non-Phyrexian spell each turn.
Non-Phyrexian creatures enter the battlefield tapped.

Pious Warrior

Whenever Pious Warrior is dealt combat damage, you gain that much life.

Amrou Seekers

Amrou Seekers can't be blocked except by artifact creatures and/or white creatures.

Archon of Emeria

Flying
Each player can't cast more than one spell each turn.
Nonbasic lands your opponents control enter the battlefield tapped.

Drannith Magistrate

Your opponents can't cast spells from anywhere other than their hands.

Oswald Fiddlebender

Magical Tinkering — {W}, {T}, Sacrifice an artifact: Search your library for an artifact card with mana value equal to 1 plus the sacrificed artifact's mana value, put it onto the battlefield, then shuffle. Activate only as a sorcery.

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Preston, the Vanisher

Whenever another nontoken creature enters the battlefield under your control, if it wasn't cast, create a token that's a copy of that creature, except it's a 0/1 white Illusion.
{1}{W}, Sacrifice five Illusions: Exile target nonland permanent.

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Trenching Steed

Sacrifice a land: Trenching Steed gets +0/+3 until end of turn.

Aven Riftwatcher

Flying
Vanishing 3 (This creature enters the battlefield with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Aven Riftwatcher enters or leaves the battlefield, you gain 2 life.

Jhovall Queen

Loran of the Third Path

Vigilance
When Loran of the Third Path enters the battlefield, destroy up to one target artifact or enchantment.
{T}: You and target opponent each draw a card.

Whipcorder

{W}, {T}: Tap target creature.
Morph {W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)