Kill 7 Idra'kess Sentinels and 7 Idra'kess Enchantresses.
I may be unable to communicate directly with the beast Nespirah, but I can still feel some things indirectly. For example, I can clearly sense that Nespirah is not happy about the naga's presence here.
When we first entered Nespirah's body, I saw dozens of sentinels and enchantresses patrolling the central chamber floor. Perhaps some of the ancient one's pain will be alleviated if you remove them.