There was a simple reason why Eren didn't include Kayara and Akel in his recent raid.
The butcher couldn't have used Skills from Beelzebub's Skill Tree if he had company.
And without the Skills he had deployed at the scene, it would have gotten much harder for him to kill all the demons along with the four demonic leaders whose heads he had presented to Jivem. Plus, he wanted to hog all the rewards that came from his kill to himself.
He also didn't want to let Ishgaar's Templars know about the mole that he had placed among the demonic den dwellers. Kayara and Akel would have reacted differently to Roza's presence if the two sides had met on the field.
Of course, the fact that Kayara and Akel were being misguided by the den dwellers was also true. Thus, Eren decided to speak the language he was good at– the language of half-truths.
