Kellen's words seemed to have a good reaction with the rest of the Guides in the room, much to the surprise of the others. Kellen didn't blame his father for his lack of understanding. As far as Kellen was aware, his father had never been kidnapped or harmed.
Kellen was very grateful for that, truly, but he also hadn't spent that much time on the front lines either. He was a classic Guide. There were some things he wouldn't be able to understand on a personal level and while Kellen was upset that these kids could understand and want pain for others, he was happy to be the one to give them that relief.
Plus, having a presence like his Dad in the room was a good thing too. Kellen's Dad fought with his words, not with his actions. That was something that most of these Guides would need training in.
