Marz is well known for his work on Silver Surfer and Green Lantern, as well as the Marvel vs DC crossover and Batman/Aliens. He also worked on the CrossGen Comics series Scion, Mystic, Sojourn, and The Path. At Dark Horse Comics he created Samurai: Heaven and Earth and various Star Wars comics. He has also done work for Devil's Due Publishing's Aftermath line, namely Blade of Kumori. In 1995, he had a brief run on XO-Manowar, for Valiant Comics.
Marz's more recent works includes a number of Top Cow books including Witchblade and a Cyberforce relaunch. For DC Comics, he has written Ion, a 12 part comic book miniseries that followed the Kyle Rayner character after the One Year Later event, and Tales of the Sinistro Corps Presents: Parallax and Tales of the Sinestro Corps Presents: Ion, two one-shot tie-ins to the Green Lantern crossover, The Sinestro Corps War.