Usher of the Fallen

Boast — {1}{W}: Create a 1/1 white Human Warrior creature token. (Activate only if this creature attacked this turn and only once each turn.)

Cathar Commando

Flash
{1}, Sacrifice Cathar Commando: Destroy target artifact or enchantment.

Monk of the Open Hand

Flurry of Blows — Whenever you cast your second spell each turn, put a +1/+1 counter on Monk of the Open Hand.

Clarion Spirit

Whenever you cast your second spell each turn, create a 1/1 white Spirit creature token with flying.

Valkmira, Protector's Shield

If a source an opponent controls would deal damage to you or a permanent you control, prevent 1 of that damage.
Whenever you or another permanent you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.

Reidane, God of the Worthy

Flying, vigilance
Snow lands your opponents control enter the battlefield tapped.
Noncreature spells your opponents cast with mana value 4 or greater cost {2} more to cast.

Reidane, God of the Worthy // Valkmira, Protector's Shield

Codespell Cleric

Vigilance
When Codespell Cleric enters the battlefield, if it was the second spell you cast this turn, put a +1/+1 counter on target creature.

Paladin Class

(Gain the next level as a sorcery to add its ability.)
Spells your opponents cast during your turn cost {1} more to cast.
{2}{W}: Level 2
Creatures you control get +1/+1.
{4}{W}: Level 3
Whenever you attack, until end of turn, target attacking creature gets +1/+1 for each other attacking creature and gains double strike.

Luminarch Aspirant

At the beginning of combat on your turn, put a +1/+1 counter on target creature you control.

Loyal Warhound

Vigilance
When Loyal Warhound enters the battlefield, if an opponent controls more lands than you, search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Faceless Haven

{T}: Add {C}.
{S}{S}{S}: Faceless Haven becomes a 4/3 creature with vigilance and all creature types until end of turn. It's still a land. ({S} can be paid with one mana from a snow source.)

Snow-Covered Plains

Thalia, Guardian of Thraben

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

Sungold Sentinel

Whenever Sungold Sentinel enters the battlefield or attacks, exile up to one target card from a graveyard.
Coven — {1}{W}: Choose a color. Sungold Sentinel gains hexproof from that color until end of turn and can't be blocked by creatures of that color this turn. Activate only if you control three or more creatures with different powers.

Arm the Cathars

Until end of turn, target creature gets +3/+3, up to one other target creature gets +2/+2, and up to one other target creature gets +1/+1. Those creatures gain vigilance until end of turn.

Intrepid Adversary

Lifelink
When Intrepid Adversary enters the battlefield, you may pay {1}{W} any number of times. When you pay this cost one or more times, put that many valor counters on Intrepid Adversary.
Creatures you control get +1/+1 for each valor counter on Intrepid Adversary.

Fateful Absence

Destroy target creature or planeswalker. Its controller investigates. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Skyclave Apparition

When Skyclave Apparition enters the battlefield, exile up to one target nonland, nontoken permanent you don't control with mana value 4 or less.
When Skyclave Apparition leaves the battlefield, the exiled card's owner creates an X/X blue Illusion creature token, where X is the mana value of the exiled card.

Portable Hole

When Portable Hole enters the battlefield, exile target nonland permanent an opponent controls with mana value 2 or less until Portable Hole leaves the battlefield.

Elite Spellbinder

Flying
When Elite Spellbinder enters the battlefield, look at target opponent's hand. You may exile a nonland card from it. For as long as that card remains exiled, its owner may play it. A spell cast this way costs {2} more to cast.