What is the fine-grained topic of the following text: After returning to the forefront of Valiant’s publishing line with a chart-topping, multiple sold-out series by New York Times best-selling writer Robert Venditti (Green Lantern, The Flash) and Eisner Award winner Cary Nord (Conan, Star Wars) in 2012, X-O Manowar anchored the resurgence of the Valiant Universe and went on to become one of the best-selling and longest-running superhero series of the modern era, earning a multitude of awards and critical accolades from the industry’s most prestigious outlets in the process. Only return the topic.
The success and resurgence of the X-O Manowar series in the Valiant Universe.