Zinnia and Meticulous Excavation on the battlefield.
You control at least seven permanents and/or have the city's blessing.
({5} magic symbol) ({W} magic symbol) ({U} magic symbol) available the first turn, with ({7} magic symbol) ({W} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) each following turn available.
Steps
Cast TImestream Navigator by paying ({1} magic symbol) ({U} magic symbol) , plus an additional ({2} magic symbol) for its offspring cost.
If you control ten or more permanents and don't have the city's blessing, Timestream Navigator gives you the city's blessing.
When Timestream Navigator enters the battlefield, it triggers, creating a token copy of it that is 1/1.
If you control ten or more permanents and don't have the city's blessing, the Timestream Navigator token gives you the city's blessing.
Activate Meticulous Excavation by paying ({2} magic symbol) ({W} magic symbol) , returning the nontoken Timestream Navigator from the battlefield to your hand.
During your next turn, repeat steps 1 through 5 one additional time.
Activate the oldest Timestream Navigator token by paying ({2} magic symbol) ({U} magic symbol) ({U} magic symbol) , tapping it and putting it from the battlefield onto the bottom of your library, causing you to take an extra turn after this one.