User blog comment:B214/Volume 23 discussion blog/@comment-190.160.185.214-20170321211038/@comment-73.160.58.215-20170321233155

Ophis, Lilith, Crom, Alivian, and I forget which of Azi Dahaka and Apophis, are dragons that took human forms. Ise is a "humanoid dragon". The key point is that they are human in appearance. Ouryuu's transformation is probably closer to Tannin in appearance. And Tengen's speculation sounds plausible as to the mechanics, though I'll add on that rather than a mere touki shroud, he might be manipulating the ki from the dragon veins to "armor" himself in something like living earth.