You Do Need power plug adapter while traveling from Cape Verde to South Sudan.

Here is Why You Need An Adapter

The outlet and plug type used in South Sudan are C and D and in Cape Verde are C and F. This is how they look like.

Cape Verde

In Cape Verde, outlets of type C and F are in use.

Type C

Type F

South Sudan

In South Sudan, outlets of type C and D are in use.

Type C

Type D