The games as we know them were released Back to Front: KAMUI (third chapter, 1999) -> RefleX (second chapter, 2008) -> ALLTYNEX Second (first chapter, 2010). But, consider the original versions of RefleX (Reflection) and ALLTYNEX Second (ALLTYNEX). ALLTYNEX was released first, in 1996, followed by Reflection in 1997, and finally, KAMUI (which is not a remake) in 1999. The series, in a way, was released in ascending chronological order after all!
Why is Panaffil so much more powerful than the other Kamui fighters? Most likely so did Xaffiquel a do some custom work on her to ensure that she is safe, even in her current form.
Considering that Xaffiquel was the one who came up with the brain fusion technology it might be safe to assume that he was forced to create the Kamui's as well. That includes having to convert his own daughter to one of them by his own hands. If that's the case then him crossing the Despair Event Horizon don't seem so far of.