The Ancient Magus' Bride: Wizard's Blue Vol. 7 (manga)

Giselle and her comrades fight to get Ao back, but they struggle to get past Flamme's Albert and Pain's fierce resistance. Meanwhile, Ao wanders the depths of his memories and the past he'd forgotten is finally restored to him. Lost beneath deep, stagnant waters, the black painting Ao created so long ago is trying to blot out the world.