Legend

Before Whitey Bulger, before Al Capone came two of the most notorious gangsters, London-based Reggie and Ronnie Kray.  The Kray Twins were the forerunners of organized crime. The identical crime-lords -  both roles played by Tom  Hardy - might have been vicious thugs but they also rubbed shoulders with the wealthy and powerful, building their empire in the East End of London. 
Similar to American gangster Al Capone, the twins accrued glamorous lifestyles to cover up their brutal killings. If you can look beyond their barbaric ways, you'd find the Kray's underlying charm.
Falling for Reggie, girlfriend-then-wife Frances (Emily Browning) tells the story as an omniscient narrator (even though she dies roughly two-thirds into the movie). Since her image of Reggie is obscured by love, in the beginning, he comes across as suave and sophisticated. Weary of Ronnie, Frances maintains her distance but still is fascinated by his quirky charm.
As Dan Jolin from empireonline.com wrote in his review, "Frances is swept up in all the glitz of their thrall over the East End. Then, inevitably, the filthy, gruesome true nature of her husband and brother-in-law is gradually exposed. Through her eyes they are heroes and monsters."
Jolin goes on critiquing Hardy: "At times Hardy pushes it close to comic caricature (the awful violence is almost played for laughs in earlier scenes, especially in a virtuoso Ronnie versus Reggie hardcore brawl) but he balances on the brink as he did with such spectacular success in Nicolas Winding Refn’s Bronson."
Again, the story is told through Frances.
It takes guts and skill to play two characters in the same film And I think Hardy does it brilliantly. The entire film would crumble if not for Hardy's magnificent acting! Legend will become legendary.