Okay okay, one more from the old days. Part of the story I never got to was Nikki's affliction ... which was typically anime-like: a demon soul snugged in with hers when she was still in the womb, and everytime she gets angry it flares up, each time in a different way depending on the situation at hand. Think like, Katie Ka-boom or something.
Anyway, her muse, Artemis, had been sent to her when she was a child to keep the demon-soul from ever emerging, but since he was locked in a closet for most of her life, this didn't go too well. On her sixteenth birthday, he gives her a big clunky bracelet that is supposed to keep her from changing. She takes it off at the wrong moment, and the whole thing comes out. She and her muse do reconcile, but she's very upset learning that he was sent to guard a demon, rather than just to be her childhood friend.
Eventually, at the supposed end of the whole comic, Nikki will have erased this demonic influence from herself through determination and maturity, and the Muse leaves her, promising never to be far should she need the comfort of a friend again. This is the only time it ever becomes clear that the Muse existed only in Nikki's mind, and that no one else ever saw him, and her friends had merely humored her when she spoke of him. It was supposed to be metaphorical for her finally growing up, shedding her past problems and disciplining her wild imagination instead of letting it run rampant across the lines of fact and fiction.
I have had scores of imaginary friends since I was a child (the first were two squabbling pixies who argued about everything and helped me everytime I had to make a decision ... my own version of the shoulder angel-and-devil). There is a comfort in these little characters inside my head, like a secret no one else ever gets to see. I always knew there weren't REALLY real ... but I could make them real by imagination alone and that was well enough. This is a predominant theme in every incarnation of Randomly Bemused ... fiction becomes fact and imagination is power.