Naga would probably have REALLY OP starting stats, growth rates and stat caps. As for classes, she would likley have the same or very similar classes to Tiki and Nowi though, so that would be her main downside, but she is pretty close to a god so they could just give her every class like Robin or Morgan. And speaking of Morgan, Naga!Morgan would be pretty awesome.
What if there were more Taguel/Manaketes in Awakening?