He needs her. Sturn brought Aleisha into the team specifically for a reason.
Acceptance of perception beyond the five physical senses has ebbed and flowed throughout history. Societies have embraced it, feared it, rejected it, and embraced it again. Right now, in Sturn’s Empire, psi is accepted and utilized.
Sturn has been exiled, banished from the hub of Khekarian Rule ten years before. Capturing a specimen of alien-native that might help the war effort, will go a long way to getting him accepted back within the Imperial Court. Having a psychic’s insights will help him to know the right moment to advance, the right people to contact and guide a safe path for his return to power.
It doesn’t matter that Aleisha is unwilling. It doesn’t matter how bad she is at it. There are truthseers to keep her in line. Anyway, she’s all he’s got.
This is Sturn’s viewpoint in The Khekarian Threat. He has no interest in respecting the thoughts and desires of anyone else. He’s Khekarian royalty, he doesn’t have to care.