Dantalion is the 71st out of Solomon's 72 pillars(Although he was the first demon to be summoned and make a contract with Solomon). He holds the title of the Grand Duke of Hell and leads 36 armies of Hell. He is a nephilim and followed by two bat familiars, Amon and Mamon. He is a candidate to succeed the throne during Lucifer's deep slumber, representing Astaroth's faction.
Having annihilated an entire tribe in his past life, Dantalion became a demon after making a contract with Lucifer and later become known as "The One Who Plays The Flute". As the only contractee Lucifer has ever had, he is Lucifer's direct descendant and possesses the power that could surpass the four kings of Hell.
During his time in William's school, he calls himself "Dantalion Huber" and participates in various sports, making him popular with the jocks.
He seems to care deeply for humans.Some bits in the anime show that Solomon and Dantalion were close, considering the fact that he was the first demon Solomon contacted with and they often spent time together in the flashback that is shown.