Superman

Superman is a prominent former hero who has been involved in a number of events.

Involvement in Story
Superman mostly operated as a normal hero, helping the other heroes during major events. In the Exile/Notch/Thanos/Darkseid event, he was killed by Darkseid, causing great sadness and a statue to be made in memory. After Dormammu destroyed the afterlives, he came back and resumed being a hero even after they were restored.

Joker and Scarecrow teamed up, drugging Superman with fear gas and planting a bomb in Lois Lane, causing him to accidentally kill her and destroy Metropolis. In retaliation, he killed Joker and formed a group of heroes who believe they should kill. When the heroes in that group were arrested, Shazam helped him flee to Sanghelios, where he became an ally of the Arbiter. He currently works with him in fighting the Covenant.