Poor naming aside, this animated film feels more like an excuse to depict violence and the gruesome death of superheroes than anything else. The story is pretty uninteresting as most of it is told through flashbacks. The present day scenes are more or less fight scenes that work as stages for different characters to talk things out, before moving onto the next beat.
The emotional depth of the characters and their motives feels hammed in as we keep being updated on them through passive flashbacks before being forced through fight scenes that would have played out the same even if we didn’t know what had happened in the past.
Simply put, flashbacks are bad and relying on them throughout your film is a recipe for disaster. Try to write now and make that exciting and if it isn’t exciting then that’s a better and bigger problem to fix.