User blog comment:B214/Volume 23 discussion blog/@comment-29963364-20170420234037/@comment-30048084-20170421194355

I don't think he qualifies as a Super Devil from what we have seen in the Main Series we have

Sirzechs: True form

Ajuka: Kankara Formula

Rizevim: Sacred Gear Canceller

and in Ex

Gasper: Balor abilities (Time manipulation, Darkness, Monsters)

So I guess from this we can assume that a Super Devil is a being that possess powers that surpass normal logic

Sutr Second is based on Sutr therefore Sutr will possess the same power or maybe greater, While the previous 4 examples don't really have something that their strength can really be compared to.