You control at least two untapped creatures, one of which must be green.
Mana Needed
({3} magic symbol) ({R} magic symbol) available.
Steps
Activate
Spellbinding Soprano's encore ability by paying ({3} magic symbol) ({R} magic symbol) and exiling it from your graveyard, creating a token copy of it with haste for each opponent you have.
Declare each
Spellbinding Soprano token as an attacker.
Each
Spellbinding Soprano token triggers, causing instant and sorcery spells you cast this turn to cost ({1} magic symbol) less to cast for each
Spellbinding Soprano token.
Cast
Sprout Swarm with buyback by tapping a green creature and any other creature you control, creating two 1/1 Saproling creature tokens and returning