User blog comment:RCM9698/How would you like AGK! to end?/@comment-25132749-20161221151418/@comment-29707934-20161221232430

Apparently, Leone could only survive for as long her transformation lasted. Its kind of weird that she couldn't regenerate, since she fused with her Teigu and has survived worse injuries during the series. Maybe it will be explained in the translations. I hope the translators are faster since this is the last chapter.