Herald of War
Avacyn Restored — rare
Creature — Angel
Herald of War rulings:
2012-05-01: The +1/+1 counter is put on Herald of War before blockers are declared and combat damage is dealt.
2012-05-01: The cost reduction is based on the total number of +1/+1 counters on Herald of War, not just the ones put on it by its own ability.
2012-05-01: If there are additional costs to cast a creature spell, such as a kicker cost, apply those increases before applying cost reductions.
2012-05-01: A creature spell that's both an Angel and a Human will cost less to cast for each +1/+1 counter on Herald of War.