Some point in the past, a character has had something terrible happen to him, usually the loss of a family member or other loved one and has sworn vengeance on the one who did it. However, getting Revenge at the time may not have been easy, often as they were too young, or weren't sure who the perpetrator was. But they still knew that the murderer has it coming, and know that someday they'll meet [...] [tvtropes.org]