Herald of War

A creature spell that's both an Angel and a Human will cost 1 generic mana less to cast for each +1/+1 counter on Herald of War.

The +1/+1 counter is put on Herald of War before blockers are declared and combat damage is dealt.

To determine the total cost of a spell, start with the mana cost or alternative cost (such as a flashback cost) you're paying, add any cost increases, then apply any cost reductions. The mana value of the spell is determined only by its mana cost, no matter what the total cost to cast the spell was.