Just one ruler needed for Italian East Africa. Styled as Emperor of Ethiopia
Colony of Italy
House of Savoy
Victor Emmanuel III (1936-1941)
But since he doesn't feature on the banknotes, it could be argued only
Colony of Italy (1936-1941)
is needed..?
Personaly, I'll prefer Victor Emmanuel being the ruler. But that's just my opinion
Sources:
https://en.wikipedia.org/wiki/Italian_East_Africa
https://en.wikipedia.org/wiki/Victor_Emmanuel_III_of_Italy