Meticulous Excavation and Mana Reflection on the battlefield.
You control up to five lands that can tap to produce at least ({3} magic symbol) ({W} magic symbol) ({U} magic symbol) .
Steps
Activate up to five lands you control by tapping them, adding at least ({6} magic symbol) ({W} magic symbol) ({W} magic symbol) ({U} magic symbol) ({U} magic symbol) due to Mana Reflection.