I would also add this: Do your homework diligently, figure out where true power lies, forget idealism , be pragmatic and work for the side that wields it, have powerful backers to sponsor your "deviant art work".
This will be by far hardest playstyle to play successfully there is very limited space for making mistakes. There is no place here for idealism, only thing that should matter to Deviant is himself. If you are prone for idealistic views of things greater than yourself and greater "good" this is probably not playstyle for you, sooner then later you will make decisions that will conflict with the life you chose in Elyria.
Personally I believe there will be very few truly excellent deviants rest will be just meat put on a grinder.
Early when I heard about the game I thought awesome I will be "talented" vampire Lich werewolf fireball casting super ninja pirate assassin....then I started paying attention... unless you are some kind of savant COE prodigy this type of play will be the most salt producing one and not on the receiving end but from those self styled "speshul badass ninja wanna bees" when they realize that game design is so heavily stacked against them. I am not saying it is not possible to be legendary deviant, but very few will ever get there.