How can you create a combo with Cayth, Famed Mechanist, Mana Echoes, Sword of the Paruns?
user
[START OF COMBO]This combo can be formed with Cayth, Famed Mechanist, Mana Echoes, Sword of the Paruns

Color identity: URW
Mana cost: {2}
Steps:
  1. Activate Cayth by paying {2} and tapping it, creating a token copy of a creature token you control.
  2. When the creature token enters the battlefield, Mana Echoes triggers, adding {C} for each creature you control that shares a creature type with it.
  3. Activate Sword of the Paruns by paying {3}, untapping Cayth.
  4. Repeat.[END OF COMBO STEPS]

Result:
  - Infinite enters the battlefield
  - Infinite colorless mana
  - Infinite proliferate
  - Infinite copies of creature tokens you control
  - Infinite untap of creatures you control
  - Infinite mana creatures you control can produce[END OF COMBO RESULT][END OF COMBO]

Other prerequisites:
  - All permanants must be on the battlefield
  - You control at least one creature token.
  - You control at least four creatures that share a creature type with the creature token.
  - Cayth does not have summoning sickness.
[END OF COMBO PREREQUISITES]
assistant