kane had the perfect platform to have MASSIVE character evolution, however the oppourtunity was wasted when they let him become the mid card rife on any of the shows.
he was portrayed as the enigmatic half brother of the undertaker, who at first couldnt talk, but then he gradually learned to speak.
when they removed his mask, they had a vast variety of avenues to take, unfortunatly the one that the creative team has took has made him look weak compared to his "masked" persona.
thats an example of the potential character development.
the biggest charactor development and evolution has to be the undertaker, from his first incarnation as a deadman, to the ministry undertaker who was more evil and malevolant, to the bike riding, chain weilding american bad ass brawler, and then eventually to the undertaker who has a 2 month program with whoever is world champ and then dissapears for another 2