Student of Warfare

Level up {W} ({W}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 2-6
3/3
First strike
LEVEL 7+
4/4
Double strike

Emeria, the Sky Ruin

Emeria, the Sky Ruin enters tapped.
At the beginning of your upkeep, if you control seven or more Plains, you may return target creature card from your graveyard to the battlefield.
{T}: Add {W}.

Ethereal Haze

Prevent all damage that would be dealt by creatures this turn.

Reprisal

Destroy target creature with power 4 or greater. It can't be regenerated.

Leonin Skyhunter

Kabira Vindicator

Level up {2}{W} ({2}{W}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 2-4
3/6
Other creatures you control get +1/+1.
LEVEL 5+
4/8
Other creatures you control get +2/+2.

Order of the Golden Cricket

Whenever Order of the Golden Cricket attacks, you may pay {W}. If you do, it gains flying until end of turn.

On Serra's Wings

Enchant creature
Enchanted creature is legendary, gets +1/+1, and has flying, vigilance, and lifelink.

Reciprocate

Exile target creature that dealt damage to you this turn.

Knight Exemplar

First strike (This creature deals combat damage before creatures without first strike.)
Other Knight creatures you control get +1/+1 and have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Knight of the White Orchid

First strike
When Knight of the White Orchid enters, if an opponent controls more lands than you, you may search your library for a Plains card, put it onto the battlefield, then shuffle.

Arrest

Enchant creature
Enchanted creature can't attack or block, and its activated abilities can't be activated.

Vengeful Archon

Flying
{X}: Prevent the next X damage that would be dealt to you this turn. If damage is prevented this way, Vengeful Archon deals that much damage to target player or planeswalker.

Plains

Graceful Reprieve

When target creature dies this turn, return that card to the battlefield under its owner's control.

Kinsbaile Cavalier

Knight creatures you control have double strike.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Wrath of God

Destroy all creatures. They can't be regenerated.

Pacifism

Enchant creature
Enchanted creature can't attack or block.

Armored Ascension

Enchant creature
Enchanted creature gets +1/+1 for each Plains you control and has flying.

Phyrexian Rebirth

Destroy all creatures, then create an X/X colorless Phyrexian Horror artifact creature token, where X is the number of creatures destroyed this way.

Victory's Herald

Flying
Whenever Victory's Herald attacks, attacking creatures gain flying and lifelink until end of turn.

Devouring Light

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.)
Exile target attacking or blocking creature.