>>49432068
>cool
Obviously.
>mature
If you mean "responsible like an adult", then... maybe? There are situations in which Aya acts with something that could be called as responsibility, following orders in MoF to confront player (although she subverts that), cancelling AFiEU in the end, Orin chapter in LE. But all of them are arguable.
If you mean "serious and motherly", then certainly not.
>mysterious
All tengu are mysterious to some extent and Aya is no different in this regard. There is a reason why it is Youkai Mountain ~ Mysterious Mountain. Aya doesn't put up appearances of being mysterious, unlike certain sage, but you can spot it when you start criss-crossing her interactions with others or see other's comments on Aya (The Grimoire of Marisa for instance). Also, she is very proud of not only her skills, but also of being a youkai, as you can see in BAiJR for instance, while Aya herself explains, in Three Fairies manga, that youkai thrive first and foremost on mysteriousness and vagueness. She is the type of person that makes you question whom she really is the more you know of her, not less.
>over-ambitious
Certainly ambitious. "Over"? consult "mature" part. Maybe the proper take would be saying Aya isn't mature in any sense, but not that she can't reign in her ambition at times either.
>busy-body
Beyond any doubt. Tengu is watching with her black eyes!
>goofball
This is the appearance she puts. Not that she isn't young-spirited, I think, there must be somewhere from all that resilience comes from. But she is much understanding and noticing more than she would let you know.
>>49432094
>negative