Juche Koreaball will be a future countryball made up of North Koreaball and South Koreaball.
In the Second Korean War, North Korea tried to fire a missle to Seoul, but failed. So they tried again with multiple nukes at the same time with the South Korean THAAD system was only able to detect 3 of these nukes and it hit many cities. Soon South Korea surrendered.
Juche was reformed during his rule though and wasn’t really the same thing of Kim Il Sung times. Korea under this Juche rule was more active and flexible with the rest of the world at the end.