While Ryan didn't feel the presence of any survivors hidden that hadn't joined the monsters' side, nor did Femradiel warn Ryan of that, he found several groups of bosses and survivors heading North. Their goal was obvious… they were going there to look for that group that Ryan destroyed.
"Now what?" Ryan scratched the back of his head. "If I keep ignoring those guys, eventually they will return to Tokyo, and I don't want to leave my back exposed to them."
There was also the question that they would hunt the survivors that Ryan helped. While Ryan didn't feel any need to help Haruna and the others again, they decided not to join the monsters' side, so at the very least, they weren't his enemies.
"If that is going to bother you all that much, you can kill the monsters, and I kill the humans," Femradiel said.
"… It isn't that simple," Ryan sighed. "In one way or another, I will be responsible for their deaths. Hah… I am sick and tired of this."