Honestly, 'y f n' in fanfic could be a random combination of letters without a widely recognized meaning. Maybe it's a made-up term by the author for a special plot element or character trait.
The Flash might initially be in denial. He's used to Batman always having a plan and his death would be a huge shock. He would then turn his speed into a tool for investigation, trying to find out exactly what happened. Green Lantern could feel a sense of loss but also be spurred into action, using his ring to try and prevent future tragedies like Batman's death. He might create constructs in Batman's memory to inspire the team.
Definitely not. Justice League is a creation of DC Comics. Marvel Comics has its own set of superhero teams and characters that are distinct from those in the Justice League.
In fanfics involving Catwoman in the Justice League, she often brings a unique dynamic. Her morally grey nature contrasts with the more traditional heroes. For example, she might be involved in a heist that has unexpected consequences for the Justice League. Her skills as a thief and her acrobatic abilities make her a formidable character in these fictional stories.
One of the top stories could be 'Tower of Babel' which shows the vulnerabilities within the Justice League when their secrets are used against them. Another might be 'The Darkseid War' that involves an epic battle against Darkseid. And 'Crisis on Infinite Earths' also has a significant impact on the Justice League's story as it reshapes the multiverse they exist in.
The Justice League typically includes well-known heroes like Superman, Batman, Wonder Woman, The Flash, Green Lantern, Aquaman, and others. These characters form the core team.
The 2017 Justice League movie isn't from Marvel Comics. It's part of the DC Comics franchise. DC has its own unique set of heroes and storylines that are distinct from those of Marvel Comics.