The spirit naga, on the verge of death, drops a fireball on herself in an act of vengeful self-destruction, which catches the baykok and naga as well as Johann, Zagathoth, and Ihrin in its blast!
Fireball explodes dealing 7d6 ⇒ (1, 3, 2, 6, 4, 2, 2) = 20 fire to everyone within 20 feet of the naga (everyone except Habiba and the two fey)! Reflex DC 16 for half damage...
Charred to a crisp by its own spell, the naga falls!