So, uh, confession time. The "dark" portraits for Nia and Toa actually trigger something bad in me pretty intensely. I never assembled their portraits. I can't even look at them. I don't want to put them on this site despite the plot relevancy.
Maybe you've been around long enough (or know me personally) to know just how much they mean to me. Maybe you haven't. But they really do mean a lot to me. Maybe too much if I'm reacting like this, but... yeah, that's the story. Sorry.
I'll leave links to KK's Pop'n database so that, if you want, you can see the portraits. They're on the last slides. This is all I can really do. (Do look around on their site, it's super super good!!)