Actually, [the voice that interjects her this time is of a female, whose hair is tied up in a scrunchie. She's wearing what seems to be a long dress with a sash and her lips seem to be curved up in amusement.] I believe Fav's words were "they can be used to revive someone close to death once."

He never specified how many people it could save. It's possible that it could have saved everyone who was close to death... once. But if they die again, then that's "twice". At least, for that specific person.