Holding priority, activate Drafna's second ability by paying 3 and tapping it, copying Timestream Navigator.
When the Timestream Navigators enter the battlefield, if you do not have the city's blessing, they trigger, giving you the city's blessing.
Activate Drafna's first ability by paying 1, returning the nontoken Timestream Navigator from the battlefield to your hand.
Activate the Timestream Navigator token by paying 2, tapping it and putting it on the bottom of your library, causing you to take an extra turn after this one.