The first downloadable solo DLC (if you ignore From Ashes and, er, the entirely new ending) for Mass Effect 3 will be released on 28 August for most platforms (29 August for PS3 users in Europe). ‘Leviathan’ promises to teach you some of the “dark history” of the Reapers and will send Shepard on an intergalactic scavenger hunt for something “powerful enough to kill” one too.
Obviously, as a person who makes it their business to kill Reapers, Shepard will be fairly interested in this. By the looks of this new trailer, this journey will take you below the ocean in a mech and include a fresh horde of Brutes and Harvesters for you to blow up. To help you out with that, the add-on will come with an AT-12 Raider Shotgun and M-55 Argus Assault Rifle.