He is the highest ranking commander of the Flarian Military. Any move will be approved or vetoed by him or a Legati Excelsis. Any move by him will be approved/vetoed by the Grand Duke. He is appointed by the Grand Duke.
How to identify a Marescallo Nobilis?
Unlike other commanders, who's rank is suggested by insignia on the shoulders or collar, the Marascello Nobilis is identified by uniform. He wears a black jacket with an adjustable belt tied like a sash where he holds his personal firearm. It also makes him unique among other officers like the Legati and Legati Excelsi, who are identified by insignia.