For now, we start with the presentation of one of the famous realms of Africa - Mali. Mali is a perfect example of the changes which we can expect to see in the future, regarding the rest of Sub-Saharan Africa.
Mali is a realm that has outlived its time of glory and is spiraling into irrelevance during the timeframe of EU4. Starting prior to 1444 with the death of Mansa Suleyman Keita, the brother of the famous Mansa Musa, Mali has been facing civil wars and poor leadership. As such, Mali has not had a good time starting in the game as they will have to face the Disaster Decline of Mali, with its crippling modifiers.
While the modifiers themselves are not the end of the world, Mali will have to face a series of events.
Now the question is: how do you end this disaster? Well, the mission tree has the solution. The mission tree is split into three parts: Reconquest of your former borders, dealing with the Disaster, and a little bit of colonization.
The dealing with the Disaster side of the tree is the one you will focus on the most in the early game as its rewards remove some of the disaster events, making the Decline much more bearable. They will remove the Pretender rebels spawning on every new monarch, make the estates loyal for your cause and remove the estate rebellions and will finally ensure that provinces, which are the core of other nations, remain loyal to you instead of revolting. At the same time, the missions of the Reconquest will push you into conquering former territory back, giving permanent claims over Macina, Jenné, Timbuktu, and Songhai. An additional bonus of the missions is that each conquest of a new territory will grant you +1 Stability as long you have the disaster active.
With the Restore the Empire mission you can finally retake your status as an Empire, and if you also finish the mission Handle the Kaabu you can finally put an end to the Decline as you have clearly proven that Mali has recovered from the disaster. Restore Mali Authority will end the disaster and gives you a -15% Stability cost and -0.05 Monthly Autonomy. After dealing with the disaster, it is time to step into Mansa Musa's footsteps and try to outperform his generosity. But first, you will need to get the income for that, and because of that, the missions following handling the inner troubles will focus on developing the main sources of income, which are Gold and Ivory.
Now that the gold question has been solved you can now relive the history and make a pilgrimage to Mecca. By ensuring that the owners of Ankara, Kairo, and Mecca have the "Sent Gift" opinion modifier, you can complete the mission Show Generosity and get an event that allows you to invest into Mecca, either adding a Great Mosque and making your own Ulema happy or adding a Counting House and making your own Dhimmi happy.
Finally, it wouldn't be a Mansa Musa experience if you don't crash the economy of a whole country. With the final mission Dominate Europe's Trade, which requires you to have a strong trade presence in either of the European trade nodes, and having 15,000 Ducats without any loan will, you can unleash the sheer amount of gold you have hoarded upon Europe!