Read more comics! Potential hooks:
- Batman wants it more
- Superman is reluctant to kill humans, including Bats
- Superman works for the US Government in some way (setting up Justice League maybe)
- Superman is weakened
- K R Y P T O / D A R K / K N I G H T
- Batman uses a powersuit
How did you forget Batman's one true super power?
- Prep time.
Bam, supes is done.