It is not possible for a player-controlled character to stop auto-attacking if the character is within range and is involved in combat. For a character controlled by the player to stop auto-attacking, one will need to move out of range, use an Art, or be in the process of helping a Toppled, Dazed, or Sleeping character. Note that auto-attacks will not occur if the character is swimming. Characters that are swimming also cannot use their Battle Arts. For Shulk, Reyn, Fiora, Dunban, and Riki, performing an auto-attack will fill the gauge for their Talent Art.