The really big difference between the slick antihero and a lab rat with a big gun is their respective level of literary awareness. Now, ideally this would mean that you had read just about everything and could outquote an English major. Have a good basis in the classic s as well as tortured stuff from the middle of the century.
Poetry is also a plus - preferably heavy on the sappy romance.
People love it when you make a tragic romantic quote after blasting the hell out of something. The odd contemporary book is a good idea too, people need to know that you are smart enough to build world-conquering devices and still have leisure time. However, avoid pulp fiction and never read science fiction, particularly if it's the kind of stuff that is written in eighteen volume sets. Oh, there are also a few essentials directly pertaining to evil science that you should read.