So I notice that in UM it mentions it is believed mortals have true names themselves. Would this be a fun mechanic to actually use or has been done? I like the aspect of learning the true name of someone and using it against them. Shame you can't use Planar Binding on Mortals. (Maybe a homebrew Outsider version)
Ultimately I came here because I want to see if it's been done or if it's a good idea. I could see many applications for this.