A Sovereign bank allows for the deposit of not just money but for minerals and other assets. A Sovereign bank can store currency in their foreign exchange reserves. They use these reserves to change exchange rates. They add foreign currency, usually the dollar or euro, to keep their own currency in alignment.
The 'Sovereign Bank' will offer facilities in Eswatini a trusted and safe location for the safekeeping and ease of banking for investors from Afica that may not have the enjoy the same peace and tranquility in their own countries that Eswatini can offer.