It does not attack, instead, it absorbs magical attacks due to it having inherent Runic. Its primary purpose is to stall the party's attacks while Air Force countdown to unleash Wave Cannon, which deals heavy Lightning-elemental damage to the party.
The fastest way to destroy the Bit is to use Edgar'sDrill, Sabin'sRaging Fist, Cyan'sFang, or have any character attack with the Ultima Weapon. All of these ignore the Bit's high defenses and will do full damage, likely killing it in a single hit due to its low HP. If the Bit is still alive when Air Force finishes charging Wave Cannon, it will be destroyed so Wave Cannon will not be absorbed.