At the beginning of your upkeep, Second Chance triggers, causing you to sacrifice it and causing you to take an extra turn after this one.
At the beginning of your end step, Yuna triggers, returning Second Chance from your graveyard to the battlefield with a finality counter on it.
Cast Clockspinning with buyback by paying {3}{U}, removing the finality counter from Second Chance and returning Clockspinning to your hand.
Repeat each turn.

Infinite turns

Lock

Yuna, Hope of Spira

Second Chance

Clockspinning

At the beginning of your upkeep, Second Chance triggers, causing you to sacrifice it and causing you to take an extra turn after this one.
At the beginning of your end step, Yuna triggers, returning Second Chance from your graveyard to the battlefield without a finality counter on it due to Solemnity.
Repeat each turn.

Solemnity

At the beginning of your upkeep, Second Chance triggers, causing you to sacrifice it and causing you to take an extra turn after this one.
At the beginning of your end step, Yuna triggers, returning Second Chance from your graveyard to the battlefield with a finality counter on it.
Activate Hex Parasite by paying {1}{B/P}, removing the finality counter from Second Chance.
Repeat each turn.

Combos with "Yuna, Hope of Spira"