How can you create a combo with Sprout Swarm, Mana Echoes?
user
[START OF COMBO]This combo can be formed with Sprout Swarm, Mana Echoes

Color identity: RG
Mana cost: {4}{G}
Steps:
  1. Cast Sprout Swarm, paying {3} for the buyback.
  2. Mana Echoes triggers as the Saproling token ETBs, adding colorless mana equal to the number of Saprolings you control.
  3. Spend the mana to cast Sprout Swarm again, convoking the new Saproling token to pay the colored mana cost.[END OF COMBO STEPS]

Result:
  - Infinite colorless mana
  - Infinite tapped creature tokens[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - Sprout Swarm must be in your hand
  - Mana Echoes must be on the battlefield
  - You control at least three Saprolings.
[END OF COMBO PREREQUISITES]
assistant