Convoke allows creatures to help cast a spell by tapping them while its costs are being paid. Each creature tapped this way pays for one generic mana or one mana of that creature's color.
Sprout Swarm can turn a developed creature board into repeatable token production, while Conclave Tribunal lets those same creatures help pay for removal. Emmara, Soul of the Accord provides another payoff by creating tokens whenever she becomes tapped.
