MTG >Combos >Pili-Pala +Heartstone +Urza, Lord High Artificer +

With all three cards in play, tap Pili-Pala with Urza's ability to add one blue mana Use this mana to pay one mana (since Heartstone reduces the activation cost of abilities) to untap Pili-Pala and add a mana of any color. Repeat the process for infinite mana.