I like the idea, I look forward to see a server success in making a turn-based rpg system
But I don't think you should make accounts on the server, I don't see the point, and people could log into other people's accounts from their Graal account and it'll probably mess some things up. Maybe I'm wrong and you have reasons for doing so, but again I don't see the point of making having to create an account on an account..
Good luck with your server!