Question regarding characters that can be applied for. What is the standing on characters that have a canon, but barely are in it? For example, this girl is part of a prototype series that is only 12 minutes long and is considered an archetype to another character in the actual series that was born from it. She has only a few speaking lines, but enough to possibly draw a personality from. However, she more than likely would be headcanon and fan speculation for the most part.

So in short: do you accept characters from prototypes and incomplete works? More information about this series in particular can be found here.