[Didn't he already explain they have lots of different types of demon, there's no particular norm for their appearance - oh. Right.

There's a pretty heavy pause, but being unable to emote in this form is helpful. At least he can't look like he's panicking. And being in this form is calming actually. But he still speaks carefully trying to choose his words while attempting not to sound upset by it.]

No. ...Those suits of armour in my heart are artificial demons. More complex creations like those require a soul to function.