One of the best is 'The Dark Knight Returns'. It presents an aged Batman coming out of retirement in a gritty, alternate future of the DC Multiverse. It's a story that challenges the traditional view of superheroes and their place in society.
DC Comics has indeed taken this step. It's part of their effort to present more diverse and inclusive character portrayals in the modern comic landscape. This move aims to reflect the diversity of the real world and provide more representation for different identities within the superhero universe.
Superman is definitely a DC Comics character. DC has built a rich and extensive mythology around him over the years. He's a symbol of hope and justice in the DC world.