When Lumian first gained the mysticism knowledge, he had placed high hopes on the Exorcism Spell. It appeared to be the perfect solution to deal with Susanna Mattise—provided she hadn't been entirely wiped out by the official Beyonders.
But it was only upon truly grasping the Exorcism Spell did Lumian come to the sobering realization that his jubilation had been premature.
The ritualistic spell was capable of banishing wraiths and even evil spirits, preventing them from tormenting a soul. But it came with two caveats. First, he needed to know the specter's real name and possess a personal item she'd held dear in life. Second, he needed ample time to conduct the ritual.
That second condition meant the Exorcism Spell was a no-go in the heat of battle. It was better suited for situations like Charlie's, haunted by constant dreams of Susanna Mattise, plagued by wraiths or evil spirits, but not on the brink of death.