Backup Agent

When Backup Agent enters, put a +1/+1 counter on target creature.

Gavony Trapper

Flying
When Angelic Quartermaster enters, put a +1/+1 counter on each of up to two other target creatures.

Militia Rallier can't attack alone.
Whenever Militia Rallier attacks, untap target creature.

Flying
When this creature enters, you gain 1 life and draw a card.

Wanderer's Intervention deals 4 damage to target attacking or blocking creature.

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Flying
When Pillardrop Rescuer enters, return target creature card with mana value 3 or less from your graveyard to your hand.

Star Pupil enters with a +1/+1 counter on it.
When Star Pupil dies, put its counters on target creature you control.