As Aeolus charged forward to join Estel in their relentless assault, the primary objective shifted from defeating Iris to simply landing a single attack with the dagger, which was enough to start the sealing ritual on her.
"For anyone who's still alive, go help elder Aeolus immediately! This is an order!" Morticia's command rang out from the rear to the disoriented Chaos Order members. Initially hesitant, they grappled with the idea of marching towards certain death.
Despite the apparent futility, they decided to charge towards Iris. Currently, their bodies served as nothing more than cannon fodder for Aeolus.
In an attempt to distract Iris, Morticia unleashed her dark magic. She knew it would likely be useless against Iris, but it was the best she could do in the current dire circumstances.