sure this is Aya and not Lord Tenma?

Aya is tagged on Pixiv

Looking pretty epic there, Aya.

Maybe Aya BECAME Lord Tenma.

Lord Tenma is not short

Are you calling Aya short here? Half her leg alone is nearly taller then Hatate.

Is there a tag for this kind of Tengu air chair sitting?

Aya is older than them?

splatwaterex said:
Aya is older than them?

Unknown as far as I know but highly likely. As far as I can remember at least, Aya is one of the oldest characters around.