Shuffle Time is a mechanic in Persona 3 Reload activated after winning a battle. It rewards the player with certain special effects or items after a battle, making raising your Personas and Social Stats much easier if you use it properly.
Persona 3 Reload Shuffle Time Explained
Shuffle Time has been present in all previous versions of Persona 3, but it has been slightly reworked for Reload. It activates after winning a battle at a random chance, but getting 1-Mores increases its chances. Finishing the battle with an All-Out Attack guarantees a Shuffle Time.