Mansa Musa is one of the most powerful rulers of the world ever.
Step-by-step explanation:
Mansa Musa was a power ruler of Mali because he is the first major ruler of the region above Sahara near to the western African region.
Mansa Musa was a power ruler of Mali but he was not from Mali. HE had been a man of the Western African region only but he came to found the empire that was based around Mali.
Mansa Musa was a power ruler of Mali so he had built an empire around Mali and his riches and prosperity had made this empire reach pout to the world far and wide.