Martial arts, “gives true answers to all questions” and “faithful to the magician who summoned him”
Depending on the version, Marchosias appears as a fire-breathing wolf with a serpent’s tail and gryphon’s wings; he can take the shape of a man, particularly a soldier; but sometimes takes the form of a she-wolf (as Le Breton shows in the Dictionary Infernal.)
Backstory! Marchosias is a fallen angel, a member of the middle-management order of Dominations (or kyriotates). When Solomon bound him, he said that he’d hoped to return to Heaven after 1200 years or so. Outside of fiction there aren’t any stories of an angel redeeming itself, so it seems unlikely.
Some of this backstory plays out in the music video, “Marchosias.” One for the furries.