The prequel to the video game! Manga by Arvid Nelson J.M.
Hellgate: London takes place in 2038, 18 years after the start of a war: London has been invaded by demons from Hell. These particular hellions are a tireless lot, and have been looking for a way into our universe for a long time. Up until recently, humans have had many champions looking to hold back the flood. Various real-world events are referenced in the background of the Hellgate story as averted crossover attempts.