You don't need to recreate the same character to get revenge. I had a character that I played years ago on FEI that was betrayed by another character. I stopped playing for a few years, and when I came back I created a new family and RPed them as the grandchildren of the original character who had grown up hearing stories about the betrayal of their grandfather. They got his vengeance for him.
I could do that, yes. But my problem with that is I don't like the concept of taking revenge just because of old family stories or the cliche "fathers journal." While everyone in the realm (including this hypothetical new character) has a reason to get revenge, it is much more personal for my original character. Overall, that makes for better, more entertaining RP.
Realistically, people are typically more driven to get revenge when the wrong happens to them personally. Can revenge be taken on behalf of another? Yes, of course. But again, it just doesn't get more personal than taking revenge for yourself.
