Samigina is a very busy demon, he is one of the many managers of the infernal plan. He is the grand master of the liberal arts that he can teach you with spiritual funding.
Its main task is to list and report souls who have died in sin. There is no shortage of work and his 30 infernal legions are there to help him. Collin de Plancy informs us that a legion makes 6,666 minor demons, or 199,980 infernal officials under Samigina's command.
Upon casting, it takes on the odd form of a dying horse or soul. However, if the summoner asks him to take his true form, he will take the one on the engraving.