IOTL Mengistu was often called Ethiopian Stalin or Black Stalin.
He had the "targetted famine" thing down cold, so he's close enough. But Mengistu never stabilised his country, as he left it a starving wreck in the midst of a massive civil war. I don't know how you could make Mengistu's regime successful. Maybe if the Soviet Union never fell and kept up foreign support, plus more stability (probably more deaths in the process), maybe Mengistu could do something good for his country.
Scary thing is he's still alive and well in Zimbabwe. He allegedly was one of the key planners behind
a series of slum clearings which displaced hundreds of thousands of people.
But have you looked at Uncle Bob over in Zim? Ethnic cleansing (sorta, many of the white farmers were murdered or left in fear of being murdered), one party politics and driving the economy to Hell , among his many achievements. (IDK if Bob did this all single-handedly or not. My gf's father (a former Zim tobacco farmer) seems to think so)
Not just whites there, also the Ndebele, who in the 80s were subject to repression, torture, and mass murder by Mugabe's North Korean-trained soldiers due to their support of Mugabe's political rivals.
Mobutu?
Zaire had tons of resources, and he had a sort of "African Stalinism" to his domestic nationalism
The key is to avoid corruption until you can actually afford it
He had the resources, he just didn't have the infrastructure or anything else to exploit them, nor the will to do much but keep himself in power and enrich himself and his associates.