Urdnan, Dromoka Warrior

When Urdnan enters, put a +1/+1 counter on target creature.
Whenever you attack, target attacking creature with a +1/+1 counter on it gains first strike until end of turn. If that creature has two or more +1/+1 counters on it, it gains double strike until end of turn instead.

Thriving Heath

This land enters tapped. As it enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Take Heart

Target creature gets +2/+2 until end of turn. You gain 1 life for each attacking creature you control.

Griffin Protector

Flying
Whenever another creature you control enters, this creature gets +1/+1 until end of turn.

Wingsteed Rider

Flying
Heroic — Whenever you cast a spell that targets this creature, put a +1/+1 counter on this creature.

Abzan Falconer

Outlast {W} ({W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has flying.

Basri's Lieutenant

Vigilance, protection from multicolored
When this creature enters, put a +1/+1 counter on target creature you control.
Whenever this creature or another creature you control dies, if it had a +1/+1 counter on it, create a 2/2 white Knight creature token with vigilance.

Plains

Sigiled Sentinel

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Vigilance

Honor

Put a +1/+1 counter on target creature.
Draw a card.

Odric, Lunarch Marshal

At the beginning of each combat, creatures you control gain first strike until end of turn if a creature you control has first strike. The same is true for flying, deathtouch, double strike, haste, hexproof, indestructible, lifelink, menace, reach, skulk, trample, and vigilance.

Valkyrie's Sword

When this Equipment enters, you may pay {4}{W}. If you do, create a 4/4 white Angel Warrior creature token with flying and vigilance, then attach this Equipment to it.
Equipped creature gets +2/+1.
Equip {3}

Kwende, Pride of Femeref

Double strike
Creatures you control with first strike have double strike.

Surge of Salvation

You and permanents you control gain hexproof until end of turn. Prevent all damage that black and/or red sources would deal to creatures you control this turn.