Well, start getting used to the fact that the Joker now has an emo band as an outlet for his psychopathy. According to Variety, Warner Bros. has at last addressed the long-running rumors about Suicide Squad's casting, and overall, the rumors were right.
As has mostly been suspected, the supervillain film's main cast will indeed consist of Will Smith, Tom Hardy, Margot Robbie, Jai Courtney, and Jared Leto--though the announcement adds to that list model-turned-actress/singer Cara Delevingne.
Smith--previously said to be playing Captain Boomerang--is signed on for Deadshot, the masked Batman villain and expert marksman whose mask is now likely going in the trash to more clearly reveal how much Will Smith got paid to be in this thing.
So, since Deadshot is taken, Courtney has been left with himself taking Captain Boomerang, the Flash rogue who does exactly what you'd figure. He throws boomerangs at people. Cartoon logically, he is from Down Under, where boomerangs are constantly thrown between gulps of Foster's and Outback Steakhouse Bloomin' Onions, so hopefully the Australian actor can at least make that aspect seem believable.
Hardy is playing Rick Flag, the generic military guy. Leto is the Joker, who is the Joker. (You've seen him in those Batmans!) Robbie is Joker's sidekick, Harley Quinn. And Delevingne will play Enchantress, a sorceress who wields the sort of magic you'd figure the studio would avoid for how gritty and serious they're trying to make all of this.
Combined, they form the titular Suicide Squad, a group of criminals who avoid jail by doing government black ops missions so dangerous, they're basically suicide. Will Smith is going to get so many opportunities to say, "Ah, hell nah!"