Would it be appropriate to put this fan art in a portfolio?

I entered a competition for Square Enix where we had to draw one of their characters (Lightning) in our own customization. Basically, we can draw her however we want (and design a new outfit), she just has to be somewhat recognizable. This is my picture: http://luigigurl.deviantart.com/art/Lightning-Fallen-435067141

I like the end result, and I wanted to add it to my digital art portfolio. Is that unprofessional to companies even though it is a very specific customization? Normally, I wouldn’t add fanart but this isn’t a direct drawing of her even though it’s supposed to still be her, so I’m not sure what it counts as.