Sienna never had to fear for her life before this day.
Her life was never in actual danger even when she was out hunting monsters for fun. Or when she was handling the clan's business. Even the mock battles she had to go through all her life never really harmed her.
So when she felt the threatening sensations from Eren's weapon, she felt goosebumps on her skin.
'I… I could die here!'
Sienna realized this as she watched Eren lose himself in his trance handling his weapons. The flying slashes he was sending around him were not lethal at first because he wasn't using his mana. But his elemental attainments were slowly starting to manifest. Soon those slashes would cause her a great deal of pain and eventually lead to her death if they land on her.
Eren started speaking up again– more for himself than for any of his listeners.