Sebastian’s true form?

In artwork for a chapter cover, during the green witch arc, Sebastian’s reflection in a mirror looks like a black or smoky dragon with large, curved horns. Yeah, for ch88:

And part of my Mother3 theory has Sebastian paralleling two major roles in the game: Boney, the loyal family dog (when he’s under contract/acting like a loyal butler) and the Dark Dragon (when he’s not under contract or when he’s behaving demonically). Here’s an older post about this topic.

So far, the manga has supported this theory quite well, including this part about Sebastian. A loyal family dog in the game and named after a loyal family dog in the manga. A powerful dragon who obeys the will of the person who gives it their “heart” and a powerful demon who obeys the commands of the person who offers it their soul. Even better that artwork, like for ch88, occasionally depicts him as a “dark dragon”. And awesome, imho, that “dark dragon” and “black butler” both use alliteration and similar adjectives.

Ah, but for the title page of ch139, he claims “I, who am nothing… can become anything.”

So, I think that it’s quite possible the demon is most-naturally an amorphous, inter-dimensional Eldritch abomination. No real shape that humans can perceive too well. An inky blob that changes shape at will. When he’s able to take a luxurious nap, he might essentially look like an inky puddle draped across its surroundings. Or the demon finds a cozy place to be contained. Much like a cat that drapes itself across the furniture… or finds a box and does the whole “if I fits, I sits” thing. 😆