Cast Time Warp by paying {3}{U}{U}, causing you to take an extra turn after this one.
Move to your combat phase, and declare Ardent Dustspeaker as an attacker.
Ardent Dustspeaker triggers, causing you to put Time Warp on the bottom of your library from your graveyard, then exile the top two cards of your library with the ability to play them this turn.
Move to your next turn, drawing Time Warp from the bottom of your library due to River Song during your draw step.
Repeat.

Near-infinite turns

Skip your draw steps

Lock

River Song

Ardent Dustspeaker

Time Warp

Cast Temporal Manipulation by paying {3}{U}{U}, causing you to take an extra turn after this one.
Move to your combat phase, and declare Ardent Dustspeaker as an attacker.
Ardent Dustspeaker triggers, causing you to put Temporal Manipulation on the bottom of your library from your graveyard, then exile the top two cards of your library with the ability to play them this turn.
Move to your next turn, drawing Temporal Manipulation from the bottom of your library due to River Song during your draw step.
Repeat.

Temporal Manipulation

Cast Capture of Jingzhou by paying {3}{U}{U}, causing you to take an extra turn after this one.
Move to your combat phase, and declare Ardent Dustspeaker as an attacker.
Ardent Dustspeaker triggers, causing you to put Capture of Jingzhou on the bottom of your library from your graveyard, then exile the top two cards of your library with the ability to play them this turn.
Move to your next turn, drawing Capture of Jingzhou from the bottom of your library due to River Song during your draw step.
Repeat.

Capture of Jingzhou

Cast Walk the Aeons by paying {4}{U}{U}, causing you to take an extra turn after this one.
Move to your combat phase, and declare Ardent Dustspeaker as an attacker.
Ardent Dustspeaker triggers, causing you to put Walk the Aeons on the bottom of your library from your graveyard, then exile the top two cards of your library with the ability to play them this turn.
Move to your next turn, drawing Walk the Aeons from the bottom of your library due to River Song during your draw step.
Repeat.

Combos with "Ardent Dustspeaker"