Who is Menoeceus (from The Phoenician Women) from Euripides V and what is their importance?

Menoeceus is the son of Creon. He is also one of only three pure-blooded descendants of the original occupants of Thebes, the "Sown Men". Because he is the last unmarried Sown Man, Menoeceus is the only person who can save Thebes from the wrath of the war god Ares, who is angered by the death of the dragon he sired. To save Thebes, Menoeceus kills himself as a sacrifice to appease Ares.