You control at least one additional creature that has haste and/or flash.
Mana Needed
({2} magic symbol) ({W} magic symbol) if you don't control a commander available.
Steps
Cast
Flawless Maneuver by paying ({0} magic symbol) if you control a commander or ({2} magic symbol) ({W} magic symbol) otherwise, giving creatures you control indestructible until end of turn.
Activate
Krark-Clan Shaman by sacrificing an artifact, dealing 1 damage to each creature without flying.
Sonic's second ability triggers for each creature you control with haste or flash that was dealt damage, creating that many tapped Treasure tokens.