What's worse, Shalltear had realized that Reiger seemed to have the ability to render mental domination and other negative effects ineffective, which made many of her abilities useless against him.
In her battle with Reiger, Shalltear successively used "Human Species Charm," "Human Species Binding," "Internal Burst," "Likely Death," "Open Wound," "Pain Wave," and "Insanity" among other spells. But these magic attacks aimed at the mind or body that could inflict negative status, all turned out to be ineffective; none had any effect on Reiger.
He was completely immune to these negative statuses and effects, immune to magical interference against both the mind and body. This was a critical reason why Shalltear was caught off guard during the battle and gradually fell into a disadvantageous position.