First Encounter Edit
Yuna is forced to switch to the Songstress dressphere and use Darkness Dance the whole battle. While Leblanc has Darkness on her, she will almost never hit with physical attacks. She can still use Thunder, which is fairly strong.
Second Encounter Edit
Leblanc hasn't gotten much stronger, but this battle is harder because Logos and Ormi are with her. It's good to still have a Songstress, because Darkness still affects them all. The other two party members should focus their attacks on Leblanc while the Songstress dances. Leblanc should be taken down first, because her attacks can hit the entire party.
Third Encounter Edit
This is the final time the Gullwings have to fight Leblanc. Once again, she is with Logos and Ormi. She is stronger since the last time she was fought. This time, the party should to take down Logos first, since he has the least amount of health and Russian Roulette, which can inflict any status ailment. If all three members are alive, they may use the No Love Lost combo, which deals heavy damage.
The player can use Grenades (preferably not Budget Grenades), which can do about 300 damage to each member of the syndicate, which is about 1/4 of her HP. It is better to use them quickly, because they will use Not-So-Mighty-Guard, which will reduce the damage done.
Leblanc (pronounced leh-blonk) is a contracted form of le blanc, "the white" in French. Blanc is the masculine form of the adjective; blanche is the feminine form.
Given her thieving nature, she may also be named after Maurice Leblanc, author of the novels about the master thief, Arsène Lupin.