For score count, I suggest making an overall estimate, i.e. judging ranks from the surface area of each character's polygon. About the extreme characters like Gildartz and Bluenote, let their offense go to C00L levels
The difference in power between the weakest mages (like Bora) and the strongest (Hades) is too much to calculate on a scale of 10. Raising it to four digits could cause some issues with the actual measuring of stats, though...