Middle Demon

Inside the tree hollow he was currently hiding in, Mark took a deep breath. 

He knew he had changed after becoming a Middle Demon. A lot. Even his appearance was no longer exactly the same—not to mention his powers that felt firmer. Previously, he couldn't see through walls with his Soul Sense but now, his Soul Sense could pierce through the hollow wood surrounding him and see the eerie and dark forest surrounding him.

And his Defensive Magic Skin—which used to be an invisible membrane surrounding his skin—had expanded. It had seeped into his bones, into the marrow, and into his cells. From head to toe, to organ to organ, he felt its presence.

It was no longer a Defensive Magic Skin, but a Defensive Magic Aura surrounding him.

As part of evolving, he had also gained the ability to use an Ultimate Demonic Art.