You each get to carve your own path in separate stories or work together in a single world with choices that do truly make an impact. (articles.gamerheadquarters.com)
They make for an enticing build up to larger fights but regardless I think to really separate the story mode from the multiplayer some new enemies would have been necessary. (mkaugaming.com)
They each have their own separate story and by the end of the game, you'll see the outcome of their actions. (stickskills.com)