User blog comment:B214/Light Novel Volume 16 spoilers/@comment-162.202.198.72-20131019090351/@comment-23847729-20140128052434

About Rizevim being a mere devil.

Correction, he is a Super Devil like Sirzech.

Meaning he a being that you can't consider as a Devil.

And that he can maybe go toe to toe with a Heavenly Dragon at it's full power.