It's 17 years after Soul Calibur IV. In the end of that game, Siegfried Schtauffen, then wielder of the spirit sword Soul Calibur, destroyed the demon sword Soul Edge and its wielder, Nightmare. In the present day, the son of series veteran Sophitia, Patroklos, is working for the European Empire destroying the malfested to try to avenge his mother (they killed her) and find his sister, Phyrra (they kidnapped her as a child). Meanwhile, Phyrra's life has been miserable since her kidnapping and everyone's trying to kill her, and her killing them to protect herself is making her a malfested. They must deal with these problems as they try to bring their family back together and survive.
There are quite a few modes in this game: Legendary Souls (an unlockable Boss Rush), Arcade Mode (6 back to back fights), Quick Battle (fighting custom enemies), Versus Mode (make your own fights), Training Mode (self explanitory), Online Mode (fight other people online) and Story Mode (explained above). There's also an extremely fleshed out Character Creation that lets you do nearly anything. Also, the fighting system is still the same as the other games.
Now onto the cons: the AI is broken. Honestly, Easy mode shouldn't feel like Very Hard mode! The characters are extremely unbalanced (Nightmare's overpowered, ZWEI's pretty much unusable, etc.)! Legendary souls is filled with the most broken characters and will take days to get through IN A SINGLE TRY! Those flaws alone make this game unplayable outside of Versus and Online Mode!
TO be honest, SCIV was much better. I mean, sure there wasn't as much options in Character Creation or modes, but at least the AI was forgivable! NamcoBandai better release a patch that gets rid of those flaws!
HBM, signing out...