As a team comprised solely of the worst criminals who hunt down people even worse than them, it's going to be difficult for James Gunn to retain Suicide Squad's PG-13 rating.
Although there’s plenty of heartwarming and surprisingly light-hearted moments in the series, there’s also some stuff that would immediately turn the whole thing into the most debauched of R-rated films. Not only is there a trend for the series to have Saw-level violent deaths, but the purpose of the team is to do things that nobody else will – generally because said things are also horrifyingly awful.
Most of the speculation surrounding Gunn's new project is likely to focus on stuff that could feature in the story, but it's always worth taking a look at stuff from the source material that's so dark and disturbed, that it'll probably never make it to the big screen.
10. Metamorpheus' Creepy Powers
Why Metamorpheus hasn’t been used properly in comics is a continual mystery, as his powers are cool enough that him only having five appearances since his creation seems a total waste. That said, they’re also powers that may belong with someone more demonic, because they're straight-up terrifying.
The villain technically has two powers - one that lets him take the form and memories of those he comes into contact with, and another that lets him contort the bones and flesh of said form into what can only be described as the stuff of nightmares. Horror fans may recognise these powers as more or less identical to that of the creature from The Thing, which hopefully goes some way in explaining exactly how unnerving said powers can be.
Given James Gunn is unlikely to change the sequel into a horror film, it’s fairly likely that Metamorpheus isn’t going to feature in the new film.