City of Heroes

In the aftermath of World War I, a man named Marcus Cole sought out the mythical Well of the Furies to cure himself of the effects of exposure to mustard gas. Marcus and his best friend Stephan Richter found the Well and accidentally opened Pandora's Box, granting themselves superpowers and unleashing the stored up potential of humanity on the world.

Nearly a century later, superheroes are commonplace. Unfortunately, so are supervillains. Following an invasion from extradimensional aliens called the Rikti, Paragon City and much of the Earth was devastated and is still in the process of slowly rebuilding. Then came the invasion of the Praetorians, a world where many of the Earth's greatest heroes conquered the world after their own disaster.

Based on the MMO City of Heroes, found here: