Hi Baron :)
This mod looks very interesting and it moved me emotionally to check it out cuz Vivi is one of my favorite characters in the whole FF saga, but some testing in-game prove your Vivi pretty OP in DD. Almost all abilities have no drawbacks and they are incredibly powerful, specially in the dark with moon rings.. you never, ever miss and one hit can single shot a whole enemy party or bring their health to half, which is obviously unbalanced...

It might be nice if you could add an ability that clears corpses causing no dmg or something for balance and synergy :)

Artwise, it might be nice as well if you could make Vivi a it shorter, it looks a bit weird that Vivi is so tall and thin in DD and her outfit is too bright, it's not very DD fitting IMO... I could see you took the Grave Robber model for the character, but Vivi is not that thin... just my opinion :)

I hope you don't take this the wrong way... I'm just giving you my honest impressions :)