To determine a spellâ€™s total cost, start with the mana cost (or an alternative cost), add any cost increases, then apply any cost reductions. The spellâ€™s converted mana cost remains unchanged, no matter what the total cost to cast it was.
If multiple replacement effects would modify what mana an ability you control produces, choose one to apply. After that, determine if any others are applicable. A replacement effect canâ€™t apply to the same event more than once this way.
Damping Sphereâ€™s second ability counts spells that were cast during a turn even if Damping Sphere wasnâ€™t on the battlefield as they were cast. For example, if Damping Sphere itself is the third spell you cast in a turn, the next spell you cast costs more to cast.