Chapter 371 is the third part of the "Nightmare Arc".
Arumio asks his brother to be patient and then also surrounds him with the spell as well. He says Nenomious' frustrations and hardships haven't even begun. He'll have plenty of time (alluding to the immortality spell he just cast). Time has passed, and Nastasha is still asleep, doctors are unable to wake her with modern medicine. Nenomious promises to cure her, though the only way may be through magic.