Superman Legacy is an origin story. It sets the stage for Superman's adventures by showing his roots, his powers emerging, and the challenges he faces as he starts his heroic path.
Superman Legacy doesn't have a one-to-one basis on a particular comic. It takes elements and themes from the broader Superman comic universe to create a fresh narrative.
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.