Even though he didn't need to talk so much to Jenilia since he could kill her easily, he remembered that she had helped him before. Moreover, she could still be of use in getting inside Triton.
There were many Warlocks here when he arrived, but Jenilia was the weakest. She was just an intern in the Warlock Council, so she wasn't close to as strong as the other Warlocks that were here.
Moreover, she was also the least threatening. If he needed to take a hostage to get some insider information, she was the perfect person. She didn't need to be concerned about her in the least.
Also, if he needed to leave one person alive here, she was a better choice since she already knew him and helped him in the past as well, so she had an advantage compared to others.
