G = Greatness. Whether your character is a godmother (of the fairy variety), a villain, or a hero/heroine, there should be some greatness about them to make them memorable characters. Greatness can be in the form of intelligence (the villain perhaps), moral integrity, actions undertaken etc. There should be something about your characters that resonates with the readers (even if it is just understanding of where the villain is coming from in terms of attitude and behaviour while at the same time not agreeing with it). There is greatness behind whatever resonates here.
H = Humour. Humour is wonderful in a story. It can provide moments of light relief. It can show up attributes of a character that would not come out necessarily in any other way. (Perhaps a character's wit here could show a good grasp of irony that they might use in a different way later in the story to bamboozle their opponents? Quick thinking and humour often go hand in hand and the former is usually vital for a character wanting to get out of a tight spot).
I = Imagination. How imaginative are your characters in dealing with others, making their plots succeed, using others to achieve their ends etc? Do they need to plan things out thoroughly or can they be intuitive? How do they handle matters when things go wrong? Can they use their imaginative skills to correct the situation?