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.
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.