Re: Here on Earth-2: your evil counterpart!
When I ran a dimention-hopping adventure, my PCs found a few familliar faces...
Vincent, the Next to Last Vampire Hunter met Vincent, the Next to Last Vampire.
Ezekiel Lao, Agent of Oracle met Emperor Lao, Lord of the Americas. Their Lao used his occult knowledge to conquer a few continents instead of fighting demons.
Dr. Benedict, occult investigator met Dr. Benedict, old man who ruined the planet. Instead of finding the amulet that turned him into Captain Mysterion in 1940, he opened the Tomb of the adversary, dooming mankind. Ooops.
Lillith, shy mentalist met her evil twin Eve, slutty mentalist. Our world's Eve drowned in a boating accident at age 6. Lao-world's Lillith died in the accident instead. Lillith stole Eve's clothes and impersonated her. She has since adopted Eve's outfit as her own.
Our Vincent stayed in Vampire World to lead the human resistance (the player had left the game.) Lillith took Eve back home and freaked out her mom.