With the help of the gods, the son of the Devil goes to earth to send the demons and creatures back to Hell that escaped after an explosion opens up a pathway for them to leave before they overrun earth and destroy everything.
Better to go with a longer logline than to have the wrong kinds of questions raised. The devil having a son is not a common idea so the point of it here should at least be hinted to. Why does the son want the demons back? How does the son act (seemingly) against his father? Why is the son needed when the gods can take care of everything?
Offer a sense of how many escape, tens, hundreds, thousands?