After remembering that the emperor himself is in on whatever it is Asahi is scheming, I'd be surprised if it didn't involve a primal of some sort. His little talk with Elidibus implied to me that he's not afraid to use them to further the empire's goals if they can be controlled and restrained.

A somewhat outlandish thought I had is that the Doman prisoners might have been deliberately allowed to be tempered by some manner of primal, and that they'll secretly be used as a catalyst for a summoning. Lakshmi's tempered showed that they're perfectly capable of maintaining a facade of sanity if it's required to further their goals.