There's not a lot of African folk in fantasy. Exceptions can, of course, be found. There are Summer Islanders in GRRM, who have dark skin, there are Tom-tom and One-Eye in Glen Cook... but again, they're more the exception than the norm. I hope the same cannot be said in the 10th Age. I've placed Zesh, the origin of mannish magic and much of its culture, quite far from the main framing of the setting. However, sea-routes do exist and have been used from the Iron Cities and the Zeshimite interior to the north. There are a number of important NPCs who are Zeshimite, the most obvious being Wah Khar One-eye, the pirate-captain turned High Master of Essad.
But trade between the Onyx Cities and the north is probably more prevalent than I've yet let on. Khewedi ships pour into Miles every month to bring grains from the desert land. Onyx Cities ships should be docking with great frequency at Noranos to exchange the secret products of the jungle lands with the men of the north. The fruit of strange trees, onyx, obsidian, and other things which can only be found south of the Red Desert fetch humongous prices. Milean nobles are particularly fond of the plumage of the rainbow dove.
The lands around the Onyx Cities are politically unstable. Oruna, the great veldtland to the south, produces great numbers of tribal warriors who upset the balance in the Cities. The Zeshimite interior is home to other hungry tribes that beset their walls. Each of the great Onyx Cities has their own standard, their history, and their own traditions. Like the infamous Free Cities of the East, the Onyx Cities also universally lack something: their own armies.
In this case, however, they pay tribal mercenaries to go to war with one another or proxy-states to do battle with their foes. They hire Mugharians and ogres, the last of the great Giants from the Iron Waste in Oruna, or northerners who can fight their wars for them. They elect powerful sorcerer-generals to lead these sellsword armies... but this tradition bears upon the north not for its effects on the cities of onyx themselves, but rather for the militarization and mercenarization of the landscape that surrounds them.
Onyx Cities Mercenary
Men of all stripes and nationalities fight for the Onyx Cities. However, a character taking this kit is most likely of Zeshimite, Mugharian, or Orunan heritage as those who come from abroad are usually higher than level one and have their own backgrounds to go with them. To become an Onyx Mercenary, a character must have a strength of at least 12, and a constitution to match.
Role: The mercenaries of the Onyx Cities cut their teeth fighting wars for their "more civilized" patrons, the Zeshimite men of the Onyx Coast. They can double as policing forces in times of peace, but they are just as frequently bandits, highwaymen, and harassers. It is difficult indeed for a LG character to maintain his beliefs as a member of one of the standard companies.
Equipment: Onyx Cities companies are outfitted in all manner of ways. Some have rigorous company standards, while others wear strange piecemeal garb and do not look at all alike. Whenever someone plays an Onyx City Mercenary, it is up to them and the DM what company garb looks like. In fact, they should create the flavor of the entire company together.
If the company requires a certain set of equipment, the PC may purchase it at half price.
Special Benefits: The Onyx City mercenary has the following benefits:
Onyx Cities Mercenaries may specialize for free in one of the following weapons: Shortbow, spear, javelin, longspear, club, large flail, bolas, net, or trident.
Additionally, as long as they remain with their company they receive free room and board (sometimes in the form of a tent and camp rations, sometimes based on the company contract).
Special Hinderances: Onyx Cities Mercenaries are obviously people who live by violence. They have a -2 reaction penalty amongst civilians, a further -2 reaction penalty against hostile city-states of the Onyx Coast. They are easily identified as mercenaries when in their garb. They must also follow the orders of their company commanders, lest they be expelled.
Wealth: These mercenaries start with 8d4x10 gold.
Races: Only humans may be Onyx Cities Mercenaries, and they must be of Mugharian, Zeshimite, or Orunan origins.