User blog comment:Gilgamesh79/Demonic Energy and Magical Energy/@comment-82.178.102.63-20170829160229/@comment-1359322-20170831173724

"“Magic-circle requires certain amount of demonic-powers…… It doesn’t require that much demonic-power. No, it’s a feat that could be done by any Devil. Even children. Transportation through the magic-circle is the first and the easiest step of being a Devil.”

W-What does that mean……?

“In other words Ise, your demonic-powers are below that of children. No, it’s so low that the magic-circle can’t respond to it. Ise, your demonic-power is incredibly low.”"

- Volume 1

Ise in Volume 1 didn't even have enough Demonic Power fora proper teleportation. But we already know Ise can use teleportation now. And Ise himself constantly says he barely has Demonic Power. So it shows that Ise's Demonic Power did increase just at a minimal amount.