User blog comment:BlackWizardZeref/Fairy Tail Zero Chapter 10: Law Review/@comment-61.8.84.218-20150422132434

I think the best answer to the "is Zeira real?" question simply lies in chapter 3, when Mavis introduces Zeira to Yuriy.

Just whatch Yuriy's facial expression when Mavis talks with Zeira, and the way he asks about Zeira like an adult indulging a child's fantasy. Also, he only answers to what Mavis says.

The first time I read this, it didn't occur to me that it could mean he can't see Zeira (I noticed something was odd, but that the answer would come later on). But after seeing Zeira interact only with Mavis, and Yuriy and his crew calling Mavis a strange girl every time she brings up Zeira, I reread this passage in chapter 3, and now I'm 100% that they can't see Zeira, even though they're aware that Mavis has an "imaginary friend"...

I think that's a nice touch from a storytelling point of view, though. It just emphasizes how lonely Mavis was, and what her meeting with Yuriy and his friends means to her. It also bring a whole new signification to the phrase "Fairies in our hearts".

Now, what I want to know is... what if Mavis was a ghost all along too? :D It find it a bit unlikely that she survived on this deserted island on her own for so long, and I've always thought these decorations in her hair looked suspiciously like wings, as in she's-not-a-human-being-wings. She didn't have them when she was a kid, and now she keeps them even when she's bathing. As for why Yuriy and the others can see her when they can't see Zeira, it would be due to Mavis' illusion powers. In any case, she wouldn't be conscious of it, just like she's clearly not conscious that she's the only one who can see Zeira.

So yeah, not 100% sure about Mavis, but definitely about Zeira. ^^