Killian wasn't happy with having to go anywhere with Cyrus to get close to him when he hardly cared for the man, but eventually, Amelia's smile as she spoke to Cyrus convinced him to get rid of the hatred he had for Cyrus just one day.
Killian, like Alastor, remained quiet while Amelia and Gina asked Cyrus about his time away. Occasionally the children would jump in to ask about when Cyrus was Amelia's guard.
In the midst of Kila questioning Cyrus about his travels through the underworld, Amelia slipped her from her lap to hold Killian's hand. She knew he wasn't pleased with her asking him to go somewhere with Cyrus for them to bond, but he wasn't complaining. He was making an effort for her and at some point, she was going to thank him in a way he would like.