To qualify as a superpower, a nation must have significant global influence backed by a powerful economy and military. Only the US and maybe China would be considered superpowers today because of their economies, military and global influence.
Their is no African country that could match either the US or China and the euroclowns would never have that happen on their watch. The closest country that can achieve that NOW is Egypt. Nigeria has the largest economy in Africa, but a massive poverty population. Egypt is probably the most powerful country on the continent due to economy and military but its ARAB dominanted.
Europe still owns Africa even after colonization through debt and taxes. Some countries are still paying colonial taxes to France.
But as of right now I rank them: Egypt, South Africa, Nigeria, EthiopiA, Algeria
Egypt is Israel's bytch and will never have nukes as long as Israel is there. South Africa is a failing nation. Nigeria has the potential to be an African world power and is already a regional power with troops deployed in west Africa and Kongo. Ethiopia is land-locked so it won't have a navy that could patrol Africa and use force-projection in the future.