Cast Time Warp by paying {3}{U}{U}, getting an extra turn after this one.
Play Mystic Sanctuary to put Time Warp on top of your library.
Activate Kefnet the Mindful by paying {3}{U}, causing you to draw a card and returning Mystic Sanctuary to your hand.
Move to your next turn.
Repeat.

Infinite turns

Lock

Mystic Sanctuary

Kefnet the Mindful

Time Warp

Cast Walk the Aeons by paying {4}{U}{U}, getting an extra turn after this one.
Play Mystic Sanctuary to put Walk the Aeons on top of your library.
Activate Kefnet the Mindful by paying {3}{U}, causing you to draw a card and returning Mystic Sanctuary to your hand.
Move to your next turn.
Repeat.

Walk the Aeons

Cast Temporal Manipulation by paying {3}{U}{U}, getting an extra turn after this one.
Play Mystic Sanctuary to put Temporal Manipulation on top of your library.
Activate Kefnet the Mindful by paying {3}{U}, causing you to draw a card and returning Mystic Sanctuary to your hand.
Move to your next turn.
Repeat.

Temporal Manipulation

Cast Capture of Jingzhou by paying {3}{U}{U}, getting an extra turn after this one.
Play Mystic Sanctuary to put Capture of Jingzhou on top of your library.
Activate Kefnet the Mindful by paying {3}{U}, causing you to draw a card and returning Mystic Sanctuary to your hand.
Move to your next turn.
Repeat.

Combos with "Kefnet the Mindful"