User blog comment:B214/Question and Answers 3/@comment-24098614-20140726045053/@comment-139.193.247.178-20140728003125

B214 actually right about Diehauzer strength, tannin notes that his power is at maou class and Diehauzer is above him so its right to call him a maou class devil

lucifer group are able to stall jabberwocky cuz ajuka has designed a counter spell so that they can damage annihilation maker beasts and it said that diehauzer "group" that stall them, it doesnt mean that diehauzer himself is in there same with sirzech cuz he is in the realm of the dead

if that isnt enough to convince anyone check this quote from kiba in vol 10

"Especially the 3rd ranked Bedeze Abaddon, the 2nd ranked Roygun Belphegor, and the 1st ranked Diehauser Belial, they are Ultimate-class devils among Ultimate-class devils who have the power equal to the current Maou"