Actually, I think the problem with Batman is that he's a certain number of essential characteristics printed in big block letters, mostly related to his history, and beyond that he has so little personality that he becomes whatever the writers want him to be.
(I can't speak so much for Kratos, not being a God of War devotee, but Batman I've followed enough of to comment.)
So, Batman.
* His parents were killed by criminals.
* He decided in the process of going to war on crime to take the bat as his symbol for its
potential for inducing fear in his enemies.
* He spent his youth studying criminology, the martial arts, and whatever other fields of athletics, science, history, etc. that happen to be necessary to push the particular story line.
* In the vast majority of storylines/universes, Batman never kills anyone as a matter of dogma.
* His "Bruce Wayne" persona appears foolish, shallow, and incompetent to prevent people from considering the possibility that he's Batman, yet despite this Wayne Enterprises usually is portrayed as a very successful company.
* He has a butler named Alfred who is an older man than he (usually portrayed as having worked for Bruce Wayne's parents) and fills whatever support roles the plot requires: combat medic, researcher, repairman, sounding board, etc.
Annnnnnd that's really about it.
Gruff, strict, and demanding, or playful, vivacious, and joking? Driven to the point of psychologically pathological obsession, or just a hard-working crusader who realizes he's the only one available to fill his niche? Is violence a tool of his work, or something he craves? Is his unwillingness to kill a virtue or a vice? Do his nocturnal habits interfere with his daily life, or is he so remarkable physically and mentally that it never comes up? Identity issues, or not? Sidekick: yes or no? Is his sidekick's presense in dangerous situations irresponsible, or has he worked out the game so far in advance and trained him or her so well that harm isn't even a serious consideration? Is Batman-level physical prowess in ordinary humans rare, or does it turn up in every villain of the week, regardless of their history? Is his relationship with the police (and the commissioner, in particular) one of friendship and trust, or animosity and suspicion?
It's all been done. Paul Dini's Batman is not Frank Miller's Batman, or Greg Rucka's Batman, or Bob Kane's Batman. Tim Burton's Batman is not Christopher Nolan's Batman (or, god forbid, Leslie Martinson's Batman.) That every different writer has been able to redefine the character depending on what they wanted to explore is part of the reason for the character's longevity, but it's also the reason the character, such as it is, leads to such frustration. (Every time some writer gets it in his head that "Batman is as insane as the villains he hunts", and thinks he's being cool and edgy, I want to slap him senseless...) The cowl and the history have a degree of consistency, but the villainous master plan that leaves one Batman reeling for a six-issue arc is so full of holes that the Batman of a previous writer would have wrapped it up in one.
He does, on occasion, show signs of life. Connections with long-term chracters, flaws and weaknesses that are human rather than merely glaringly obvious plot points. But wait a year, and we'll be on to something entirely different. (Ooh, now he's dead... Yeah, that'll stick.)
While I like Batman, it's pretty perverse that even Superman seems to have a more consistent personality. Kratos at least has the excuse of an action game riding on his back and a relatively short plot arc.