Chaos Wars is a tactical role-playing game released by Idea Factory for the PlayStation 2 in Japan on September 21, 2006. Promotional art for the game is by Nishimura Kinu. The game's opening theme Shūtan no Ou to Isekai no Kishi ~The Endia&The Knights~ was done by Sound Horizon. In North America, the game was released on June 3, 2008 as a GameStop exclusive.
Chaos Wars is a crossover between several companies' role-playing game series, including Aruze's Shadow Hearts, Atlus's Growlanser, Idea Factory's Blazing Souls, Gakuen Toshi Vara Noir, Spectral Force, Spectral Souls and Hametsu no Mars, and RED Entertainment's Gungrave and Shinsengumi Gunraw Den.
Source: Wikipedia, "Chaos Wars", available under the CC-BY-SA License.