User blog comment:B214/Question and Answers/@comment-24.2.168.254-20140102070939/@comment-1359322-20140102074359

Akeno is a Devil and she can still use Holy Lightning too. -_- Even if a human or other species reincarnate into a Devil, they keep their original abilities, so the purification can't affect Koneko. Considering that it does, she's using Senjutsu so she can temporarily use it to remove her Devil powers, so that she doesn't get affected by it.