Yeah that was my thinking too
Okay, from re-reading the MC and I4 entries and my memories of the Al-Qadim
City of Brass box set that I can't be bothered to pull out of my collection, the customs and behaviour of a Noble Efreeti is pretty well covered by the
Description of standard Efreet in the 5E
Monstrous Manual.
Anyhow, here goes nothing…
Description
A giant man-shaped being roughly three times taller than a human but far wider, an efreeti firelord looks link a common efreeti apart from being exceptionally large and muscular. Firelords are among the most powerful of efreet, second only to the Sultan of the Efreet, and are even more cruel and arrogant than common efreet. As befits their rank, they normally dress in exquisite raiment adorned with massive jewellery. Firelords flaunt the power of their bodies to display their pride and status, so their garments are cut to display their muscular strength or physical beauty as much as decency and the temperature permits; they only wear all-encompassing clothes such as cloaks or robes when it is too cold to do otherwise, or if they need to hide their identity. Efreeti firelords always have weapons to hand, usually a massive falchion in a shoulder harness.
Luxurious Despots. Firelords are tyrannical rulers who rival the devils of the Nine Hells in their ruthless autocracy. They reside in fortress-like palaces with many luxuries and treasures on the Elemental Plane of Fire. As well as powerful guards and servants, a firelord's castle is crammed with costly slaves to display the ruler's importance. Many of these slaves are foreigners to the Elemental Plane of Fire who need magical protection to avoid being burned to ash. This protection must be renewed every week, forcing the slaves to seek the "grace" of the firelord or die in flames. Obviously, this makes escape very difficult.
The highest ranking firelords are the six Pashas of the Efreet who serve as viziers to the Grand Sultan in the City of Brass. The rest of the firelords are viceroys or satraps, some of whom rival a Pasha in personal influence and maintain mansions in the City of Brass. The least powerful only have a single palace in some distant territory.
Most efreeti firelords have responsibility over military outposts on the Prime Material Plane. These outposts have a luxurious chamber reserved for the firelord's exclusive use. However, firelords loathe visiting the Prime Material and do so as little as possible.
Lords of War. Firelord efreet have studied warfare since their youth and love to fight. Expert in all manner of military strategy and tactics, their love of bloodshed is so great that they prefer the thrill of personally engaging in battle to directing their forces from a palace or command tent.
Firelords are superlative schemers whose political plots are as cunning and devious as their military trickery. They spend a great deal of time plotting against other high-ranking efreet and vying for the favor of their ruler, the Grand Sultan.
Masters of the Hunt. Apart from war, an efreeti firelord's favorite recreation is hunting, a pastime they pursue on both the Elemental Planes and Prime Material. Firelords tend to leave the tedium of tracking, cornering and wearing down prey to servants and hunting beasts, and only step in when it's time to enjoy the pleasure of the finish. A hunt's aim may be to capture slaves, kill creatures, or execute "criminals," and some firelords even hunt their own slaves out of simple boredom. Efreet gleefully slaughter intelligent creatures while hunting, and consider disrespect or defiance from mortals a crime worthy of death.
That ended up a bit wordier than I initially planned, but I kept on thinking of fluff to add.