Sasha and Levi didn't want their child to grow up without Brie and Sora around. On their first day in Paradise they worked out a deal with Athena. They were happily living on Vena, the other uncursed planet of vampires. The only difference was vampires were the only race that existed and they were able to live off a consistent blood supply, like water on other planets.
The goddess Selene created this planet for vampires like the Earth was created for humans or Exteria was created for multiple races. The oceans were a sea of blood, waterfalls, all of it; it was all fresh elven blood, uthra or human blood Selene worked into the planet's infrastructure.
