Activate Timstream Navigator by paying {2}{U}{U}, tapping it and putting it from the battlefield onto the bottom of your library, causing you to take an extra turn after this one.
Declare Cynical Loner as an attacker, or tap Cynical Loner by any other method.
At the beginning of your second main phase, Cynical Loner triggers, causing you to search your library for Timestream Navigator and put it into your graveyard.
Cast Timestream Navigator from your graveyard by paying {1}{U}.
Repeat each turn.

Infinite turns

Lock

Combos with "Cynical Loner"