Once upon a time, when the land was in peril, the Council sent forth a stone that gave an ordinary person extraordinary powers.  The person, known as The Keeper, had to qualify for 3 characteristics: Innocence, Pureness, and Love.  Once these were found in a person, s/he could become the chosen one.  However, the Council had enemies who were great in power and seeked to use the stone in the name of chaos.