Shiny Happy People
The first line of the book tells us about Wanda's species: "Because he was a soul, by nature he was all things good: compassionate, patient, honest, virtuous, and full of love" (Prologue.1).
That's a little bit of species pride talking; it's not exactly 100% true. They're also a bit conceited and megalomaniacal, thinking they're the best solution to solve a planet's problems by moving in, killing its dominant species and taking over their bodies. And, truth, their society is idyllic, and near perfect. There's no more crime. No poverty. Fantastic health care. They don't even use money. Everyone takes what they need, and nothing more. But is harmony worth the price?
And if you ask us, it's a little bit ironic that the souls have strangely Native-American-sounding names, like Fords Deep Waters. Petals Open to the Moon. Glass Spires. Lives in the Stars. Rides the Beast.
This is a species that has left its native planet and is bent on galactic domination. They're a little more Christopher Columbus than they are Native American. The souls believe they have good intentions, but they're paving a road to a living hell for the remainders of the human race.