The Necromancer named Sybeth appeared before them asking the party to leave the cave as soon as possible without explaining anything. Since their initial mission was to gather a handful of magic crystals, falling back was not an option.
"What if we said no? Are you going to knock us down or kill us right here and now?" Arion may have realized provoking the enemy wasn't the best choice, though he had some sort of plan in mind beforehand.
The way he acts rashly means he already calculated the outcome. It means the Ancient Necromancer had some sort of ulterior motives, and as such circumstances, she couldn't rashly obliterate their party in one fell swoop.
"Hm... I shall... I shall..." The subtly inflection change of her voice was clear inside the cave, they'd hear her stutter a little bit
