Recently I've "met" someone online who is a Muslim / Rasta / Ethiopian Orthodox Christian. (I'm not sure if that does justice to exactly how he identifies). But he did put forward the interesting notion that Haile Selassie was the Mahdi. He was basing his views on statements from Ibn al-Arabi, and hadith about an Abyssinian being prophecies to destroy the Kaaba along with other sources.
I don't agree with that position, but I wonder if it we could view him as a sort of antitype to Ashama, the Negus of the first Hijra.