The Anti - Monitor is a highly notable character, as he is the main villain causing the Crisis. His power is immense and he poses a great threat to all the Earths in the multiverse. Another notable character is the Flash. His speed is not only useful in battles but also in some key moments of the story where his ability to move quickly is vital for the survival of the multiverse.
Superman is a very notable character. His strength and leadership play a crucial role in the events of the story. Batman is also important. His strategic mind helps in the fight against the threat to the multiverse. And Wonder Woman, with her combat skills and sense of justice, is a key figure among the heroes in this graphic novel.