Death of a Crescent Moon

Long ago demons roamed the earth freely, terrorizing humans. Humans were on the brink of extinction when a group of defenders arose. They pushed demons back to the demon realm and for generations defended the gate from a demon invasion. But with each passing decade the people soon forgot and the powers of the defenders weakened. Now the demons are planning a great return. Can the few defenders left protect the human realm? Or will it once again fall into chaos?