User blog comment:B214/Question and Answers 6/@comment-207.242.44.6-20181214200140/@comment-37165251-20181217225033

That is unclear. He is probably stronger than a twelve winged "normal" Angel (with white wings) and we know he is able to hurt a Superdevil (Rizevim at least) ...but if he is on Superdevillevel is unclear.

It is said in DxD Zero that when Grafia and Serafall where fighting each other that the Devils that saw the fight were asking if those two are even Devils anymore...so official they both count as Maou class...but the reactions show that they may be slightly above.

I think it is similar for Michael...that he is stronger than a regular Maou class, but it is unknown if he is on lower Superdevil-Level like Rizevim Lucifer.