Genghis Khan and Attila the Hun have also been noted..
Actually, I'm not absolutely sure Nostradamus actually claimed this would be the 3rd AC.. Just the last..
There may have been more than 3..
Napoleon, however, was definitely considered one of the AC's, by Nostradamus..
Likewise, Hitler..
Regardless of the number, each and every one was recognized as a threat to mankind...
In the case of Attila, and possibly Hitler, also a threat to Christianity..
Many are said to have been moved by the spirit of anti-christ such as the leaders and people of all of the "hordes" i.e., that of the great Khan, Attila and the Huns, and the various hordes of Muslims especially the Mamelukes.
Napoleon, Franco, Hitler, then the last AC will be in the blue turban..