Take Up the Shield

Put a +1/+1 counter on target creature. It gains lifelink and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Thriving Heath

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

Swift Response

Plains

Banishing Light

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

Steadfast Sentry

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

Urdnan, Dromoka Warrior

When Urdnan, Dromoka Warrior 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.

Ajani, Adversary of Tyrants

+1: Put a +1/+1 counter on each of up to two target creatures.
−2: Return target creature card with mana value 2 or less from your graveyard to the battlefield.
−7: You get an emblem with "At the beginning of your end step, create three 1/1 white Cat creature tokens with lifelink."

Sandsteppe Outcast

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

Gavony Silversmith

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

Patron of the Valiant

Flying
When Patron of the Valiant enters, put a +1/+1 counter on each creature you control with a +1/+1 counter on it.

Squad Captain

Vigilance (Attacking doesn't cause this creature to tap.)
Squad Captain enters with a +1/+1 counter on it for each other creature you control.

Generous Pup

Vigilance
Whenever one or more +1/+1 counters are put on Generous Pup, put a +1/+1 counter on each other creature you control. This ability triggers only once each turn.

Angelic Cub

Whenever Angelic Cub becomes the target of a spell or ability for the first time each turn, put a +1/+1 counter on it.
As long as Angelic Cub has three or more +1/+1 counters on it, it has flying.