Use {6} to activate Planar Portal to find Beacon of Tomorrows.
Cast Beacon of Tomorrow for {6} {U} {U} and have it shuffle into your library.
Pass to your next turn.

Infinite turns

Planar Portal

Beacon of Tomorrows

Use {6} to activate Planar Portal to find Nexus of Fate.
Cast Nexus of Fate for {5} {U} {U} and have it shuffle into your library.
Pass to your next turn.

Nexus of Fate

Activate Timestream Navigator by paying {2}{U}{U}, tapping it and putting it on the bottom of your library, causing you to take an extra turn after this one.
Activate Planar Portal by paying {6} and tapping it, causing you to search your library for Timestream Navigator and putting it into your hand.
Cast Timestream Navigator by paying {1}{U}.
Repeat each turn.

Combos with "Planar Portal"