Shaka kaSenzangakhona (Zulu) has returned to the Civilization VI leaders list and he was a feared and ruthless leader of the Zulu. In fact, the Zulu song goes:
He is Shaka the unshakeable,
Thunderer-while-sitting, son of Menzi
He is the bird that preys on other birds,
The battle-axe that excels over other battle-axes in sharpness,
He is the long-strided pursuer, son of Ndaba,
Who pursued the sun and the moon.
He is the great hubbub like the rocks of Nkandla
Where elephants take shelter
When the heavens frown... (wikipedia)
His wondrous fashioning of the Impi (ibutho) warriors made his armies a terror across the plains. Using the "bull buffalo" formation, the warriors would flank the enemy and eventually overwhelm them from multiple sides. They are one of the only African armies to lay waste to a British contingent - who were armed with rifles and bayonets. As such, the game awards the Impi troops with bonuses to flanking, ease of creation, cost, and maintenance.
Shaka Zulu lived 40 years and was eventually assassinated by his brothers Dingane and Mhlangana. Will his reign end abruptly for you as well?, or will Shaka become an unrivaled conqueror? In Civilization VI, you can find out.