Superman

Superman was once a member of the Justice League, but the team was disbanded when one of the members, using personal information of his teammates, betrayed the League causing a mysterious, but tremendous, tragedy.

During the early days of the Magistrate's anti-mask war in Gotham, Superman visited the city to ask for the help of Batman: he wanted to investigate on a drug called the False Face Serum, which was causing terrible side-effects to a lot of people in both Gotham and Metropolis. The investigation led to Superman meeting a man called Mr. Toad, who tricked him into believing he was a victim of the Magistrate, while instead he was working for them. After gaining Superman's trust, the man stabbed him with a Kryptonite knife and imprisoned him inside a Kryptonite chamber, to make experiments on him.

With his son Jon Kent taking over his role as hero of Metropolis, Kal-El was imprisoned by Mongul inside one of his warworlds, forced to fight at a non-stop pace for his life, while also completely depowered.

At some point before the 853rd Century, Superman empowered himself to an unprecedented degree using the sun's energy, and adopted the name "Superman Prime". He battled The Unkindness, but was overwhelmed by the Seven Deadly Sins.

At the end of time, Superman--having shed his Prime form--aided Wonder Woman in a final battle against Darkseid. He fought Darkseid in the heart of Earth’s dying sun, warning Diana to stay back. The sun exploded, killing them both. Diana believed that with the Earth gone he had nothing left to fight for.