Well I can't give a judgement on the character as I don't know their true name, and who they are as a character and they have to be as such. They cannot be actually full custom characters like some no name from the counter force or whatever. There must be some myth, or legend, or real life proof some sort of backing to be accepted as a character for this rp.[@The 42nd Gecko] As for the wish section just because they aren't fighting for a grail doesn't mean they still don't have an objective they want. The master in 'my room' for fgo would say 'well what do you like the most' and Atlante would say children, and hope for them to be safe as a wish.

Edit: The above is only for servants masters can be fully custom.