The new trailer for James Gunn's Superman is arguably DC's strongest and most powerful character, especially on the heroic side, as he's largely immune to damage by any conventional means. Earth's yellow Sun grants the Last Son of Krypton many extraordinary abilities, with one of his only real weaknesses being the substance known as Kryptonite, illustrating why Lex Luthor tends to have some on hand at basically all times.
To some though, Superman's nearly invincible nature is what makes the character boring and hard to get invested in, as there's little element of fear about whether he'll survive a big battle or not. That said, Superman has died more than once in both DC Comics and their screen adaptations, so clearly some villains have his number. From the sound of things, The Suicide Squad's Bloodsport (Idris Elba) is one of those villains, at least as far being able to put Clark Kent in the hospital.
The full background will hopefully be revealed onscreen in The Suicide Squad, but Bloodsport is said to have shot Kal-El with a Kryptonite bullet, the only type of gunfire capable of penetrating his normally bulletproof skin. Nothing is mentioned about Superman dying though, which makes sense, since a similar scenario happened in the 2012 DC animated movie Justice League: Doom, and a solution was found to save him.
In Justice League: Doom, Superman is lured into a trap by Metallo, who pretends to be a disgruntled Daily Planet employee considering suicide by jumping off the roof. The villain got the drop on Superman by turning his hand into a gun and shooting the Man of Steel with a Kryptonite bullet. Superman sustained potentially fatal injuries as a result of the attack, falling out of the air and smacking right into the ground with a thud. Medical first-responders attempted to save the superhero, but naturally, his skin proved impenetrable to their standard surgical equipment.
Thankfully, Cyborg and Martian Manhunter were able to utilize a Kryptonite-powered laser to successfully remove the lethal bullet from Superman's body. Since Superman survived Bloodsport's Kryptonite bullet attack in the world of The Suicide Squad, that means that a method close to the one from Justice League: Doom must've been employed in order to save his life, whether utilized by Cyborg, Batman, or one of the DCEU Superman's other established allies. With that in mind, it's easy to see why Bloodsport received a harsh jail sentence, as even beyond just attacking Superman, he damaged him to the point of requiring special intervention.
