Sunhome Stalwart

First strike (This creature deals combat damage before creatures without first strike.)
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

Parhelion Patrol

Flying
Vigilance (Attacking doesn't cause this creature to tap.)
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

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.

Sandsteppe Outcast

When this creature enters, choose one —
• Put a +1/+1 counter on this creature.
• Create a 1/1 white Spirit creature token with flying.

Banishing Light

When this enchantment enters, exile target nonland permanent an opponent controls until this enchantment leaves the battlefield.

Gird for Battle

Put a +1/+1 counter on each of up to two target creatures.

Steadfast Sentry

Vigilance (Attacking doesn't cause this creature to tap.)
When this creature dies, put a +1/+1 counter on target creature you control.

Light of the Legion

Flying
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)
When this creature dies, put a +1/+1 counter on each white creature you control.

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.

Mikaeus, the Lunarch

Mikaeus enters with X +1/+1 counters on it.
{T}: Put a +1/+1 counter on Mikaeus.
{T}, Remove a +1/+1 counter from Mikaeus: Put a +1/+1 counter on each other creature you control.

Plains

Battlefield Promotion

Put a +1/+1 counter on target creature. That creature gains first strike until end of turn. You gain 2 life. (A creature with first strike deals combat damage before creatures without first strike.)

Swift Response

Gavony Silversmith

When this creature enters, put a +1/+1 counter on each of up to two target creatures.