The cloud floating above a demon has its soul in it. If you can manage to get through to the demon, to make it see that it doesn't have to be evil, it might remember who it is and return to the spirit it once was.
You shout out and beg its soul for help until, finally, you see the cloud take the shape of a condor (こん). Aha! "You were a condor before you became a demon! Remember who you are and turn back!"