A Shakespearean View: Batman and Joker, and what TDK will be.

[El Payaso]

One element I´d like to add is Shakespeare also often made villains with deformities, which is something common to Batman villains as well, Richard III is a good example again.

A child from a noble family who was born deformed and was put away from the power it was meant for him. That later comes back for revenge cheating and killing men and even children to recover that very power he lost because of his deformity. Sounds a lot like Batman Returns's Penguin.