The french for "the returned" would be "les revenus/ceux qui sont revenus". And "les revenants" could be "the revenants/the returning ones". But I'm not an expert in English.

Euh… I'm french, and the use of "les retournés" to refer to people that return sounds weird to my french ears. We never say "les retournés" to refer to people who return. And we use "les revenants", "un revenant" only to refer to dead returning from death, or to people who let you down during a critical moment and…