Iron Man

Tony Stark, better known as his superhero name, Iron Man, is a former superhero who had a tragic history as a superhero, as the world corrupted him, and he once turned to villainy.

Involvement in Story
During the first Thanos arc, he attempted to use the stones for his own purpose, saying he "created the stones" so he would keep them for himself. Kratos killed him, and he stayed in Valhalla. Until then, he taught Spider-Man, who had become evil as well, magic powers he somehow obtained.

Canonically 2 years after this happened, Tony Stark eventually was resurrected, and came back to life. He realized Spider-Man was killed by the Sinister Six, and he decided to change, believing Peter died for a reason.

Another year later, Thanos attacked, and he and the Guardians of New York attempted to stop Thanos's army, and they succeeded, but Thanos was able to get away. He got onto Ebony Maw's Q-Ship, and killed him, and eventually got stuck on Titan.

He fought Thanos on Titan, but eventually, Strange gave up the stone, so Tony and the others could be safe from Thanos threatening to kill them all.

After the snap, Tony was stuck on Titan, until he was rescued by Captain Marvel, and taken back to Earth. He eventually fought Thanos on Titan again, along with everybody else, now revived, and they won the war, after Shazam snapped and sent Thanos to limbo.

After the war, he retired as Iron Man, and currently lives a quiet life, out of the public's eye.

This was the case until he got involved with the Crisis occurring throughout the universe, in which he was murdered by Anti-Monitor, He was given a funeral and has not had any presence since even in the afterlife.