Eren's mana reserves were dwindling while he was under the effects of the state of epiphany.
He had no real control over using his ability. It was his subconscious mind that was using it whenever it felt like it. It would expend a huge amount of mana when casting the debuff on Alephee, who would be able to get rid of it through her own means.
Alephee was happy for Eren while he was in that state. She didn't disturb him even after he kept on attacking her subconsciously while using the full potential of his ability to cast a debuff on her. She was sure that if it was any other Adept ranker in her shoes, he had been butchered by Eren's current state.
Alephee had decided to let Eren snap out of his state himself. And she was doing everything she could to maintain just the right amount of pressure on him by casting her attack spells.
Fire Snake!
