An opponent has a creature card in their graveyard.
({2} magic symbol) available.
Steps
Activate Necrogenesis by paying ({2} magic symbol) , exling a creature card from an opponent's graveyard and creating a 1/1 Saproling creature token.
Activate Krark-Clan Ironworks by sacrificing the Saproling, adding ({2} magic symbol) .
Activate Void Attendant by paying ({2} magic symbol) and putting a card from an opponent's exile into their graveyard, creating a 1/1 Eldrazi Scion creature token.
Activate Krark-Clan Ironworks by sacrificing the Eldrazi Scion, adding ({2} magic symbol) .