An over-the-hill hitman faces off against a younger clone of himself.
Beyond the synopsis: What we know so far sounds like a cross between 'The 6th Day' and 'Looper'. However, unlike the latter film where the main character was played by both Bruce Willis and Joseph Gordon-Levitt, Will Smith will be playing both roles with CGI being employed to make his clone appear as a younger-looking version of himself. Given that Will Smith ages almost as slowly as Sir Patrick Stewart, the de-aging CGI being used will likely look quite convincing.
Until we find out more, I'm potentially billing this as "Deadshot goes on the hunt to kill The Fresh Prince of Bel-Air".