The phrase "fallen creature" refers to a person or being who has become morally or spiritually corrupted and is no longer pure or innocent. Full definition
Humans came to be seen less as fallen creatures living in a fallen world and more as autonomous, rational beings, capable of choice, of doing good of their own free will, and of creativity. (religion-online.org)
Then the Traveler's ancient enemy, the Darkness, arrived and brought with it a horde of fell creatures such as the Fallen, the Hive and the Cabal. (gameplanet.com.au)
Jesus saw us through God's eyes, as fallen creatures squabbling over petty earthly things. (relevantmagazine.com)