User blog comment:Agent-Kai/Agent-Paladin Industries Q&A/@comment-25627885-20150218030505/@comment-25127732-20150218042019

"Uh.. That's not in our ability to control, man.," Kai told the unit.

"Yeah, sorry, man. Only characters made by Zion can join.. Mostly because he IS essentially Agent-Paladin Industries.," Grail explained.