Indrah has been Vishnu's second in command, probably since she became Harmony Goddess. However, his sohma turns dark and he turns against Vishnu and sides with the Asura gods. Whether he actually was an Asura god all along, or becomes possessed by back sohma, like Gai, is open for debate. There is also the possibility that this Vishnu or Brahma planned this from the beginning, to set off the events that led to Brahma's successor coming to power.