That and the characters representing a series are completely made up for that game, so adding Sonia would look too awkward. And for the above mentioned.
Though as far as characters representing a series, it seems the fuuma girl and kokoro are the only ones who are representing other konami games cause i don't see any other girl representing any other series. Though maybe i'm wrong, aside from maybe one of them representing the vic viper.
what 90's had mostly Americanized Anime Games? I remember the 90's having hand Drawn Stuff with loads of effort.
you must be talking about the 00's
There's a number of video games that were ported to the US that had animeish art in Japan but had different artwork when it was ported to the US. Look at Final Fantasy Legend to see what i mean. Btw, i meant artwork, not anime games in general. Though a good example of an anime game fully becoming americanized is one of the ranma games for the snes.