Blacker than the night
It could be a tribute to RJD, who died three month before the release of The Final Frontier. There's a song with the same title in Master of the Moon, Dio's last studio album, and if someone has to be called King in the history of their genre he is surely Ronnie. Anyway three months before the release TFF should have already been completed in great detail, so it's more likely that they just changed the title and that the lyrics have nothing to do with him. (that would explain why the worst song of the album should be tributed to the best singer ever)Are there other theories about who he is?
What makes me sceptical is that if that was true then it would have been said by the band to the point of exhaustion.