The Redeemed are Prometheans that have become mortal again, an existence also known as the New Dawn. Redeemed are effectively mortal, although they do retain some abilities (or boons), depending on the Athanor they built during their Saturnine Night. Any Transmutations are lost (due to the Redeemed's low amount of Azoth) and they do not incur Disquiet in other mortals, supernatural creatures and the environment, as they are not "rebelling against nature".
The method of becoming a Redeemed is different for every Promethean, depending on their Pilgrimage and milestones. The one requirement all Created do have in becoming Redeemed is to make at least one other Promethean.
Only a small fraction of Redeemed retain their Promethean memories, most losing them once they become human again. Redeemed may also suffer Disquiet when in the presence of Prometheans, even if there is memory retension; however a few Redeemed have shown immunity to Disquiet's effects.
Because they are human, the Redeemed can be embraced by vampires or Awakened; doing so will result in the loss of the Redeemed's boon. Redeemed can also be turned into Prometheans again. Occurences of this are quite rare; any bodies of Redeemed used in this manner bear a higher-than-average chance of becoming Pandorans during the transformation. In addition, as in any of the above situations, any boons the former Redeemed have are lost.