Hail of a Thousand Knives

Spell stack {w} (You may cast this spell as a sorcery for {w}. If you do, place it face down on
the battlefield as a 2/2 creature with; When you cast another non-creature spell, you may flip
this spell over and cast it for its spell stack cost.)
Deal 1 damage to target opponent and each creature they control. Deal another 1
damage for each stacked spell you cast at
the same time as this spell.