Well, yes the universe is altered, but people's personalities remained the same, or at least close to what it had been given the circumstances. Bruce Wayne's personality is pretty simple. He's a rich man who is willing to give any amount of money and make any personal sacrifice to get revenge on the criminal who killed his parents and all those like him. It doesn't have to be the death of his parents that makes him want revenge on the general population, it could be something else, but I put the restriction of personalities remaining the same/similar on everyone else so I have to do the same for you. The only person who didn't have that restriction was UnseenShade and that was because her character died and had their body inhabited by two people who melded into a new personality, so there was reason behind that one, everyone else, though, had to have a similar personality to their base character.