Casanova is another thing that I will call a love letter to comics. You really get a sense that Fraction just loves the hell out of comics in the way this is written (including the statement 'I love Comics' actually appearing in the book, but that isn't what I am talking about). You get a lot of fun comic conventions all over the place in this. Mad scientist, evil mastermind, super spy, robots, giant robot, time travel(time/space/dimensional travel), life model decoys, multiple earths, death that isn't final, psychic duels, advanced civilizations, and much more are packed into this story.
Casanova Quinn is the son of the leader of the big law enforcement organization E.M.P.I.R.E. His sister Zephyr is also a super spy/agent. After his sister is killed, Cass is pulled into another timeline where the Casanova there had been killed, and the Zephyr there had not. From that point he is enlisted by Newman Xeno to be a double agent, and to run missions for W.A.S.T.E. The AIM to EMPIRE's SHIELD. The missions are sometimes just piggybacked onto his EMPIRE missions, but are often counter to the objectives. He is constantly facing off against his sister and Xeno and other elements. When the volume ends he is in a good position to start anew, with a base of operations and a freshly assembled team.
It's a romp, a wild ride, it's a well done story with a lot of humor and a great deal of cleverness about it. The art is by Gabriel Ba and works very well with the story. If you've never read it, here is a link to a good CBR article on it that includes a preview of the entire first issue