Abu Hurairah reported,
The Prophet ﷺ said, "The most despicable name in the sight of Allah is that of a man who calls himself King of Kings, for there is no true sovereign except Allah 
."In another narration, "The vilest of names on the Day of Resurrection in the sight of Allah will be that of a man who called himself King of Kings."
Azami 14524
Sahihعن أبي هريرة
عن النبي ﷺ قال: إن أخنع اسم عند الله رجل تسمى ملك الأملاك، لا مالك إلا الله عز وجل. وفي رواية: أخنى الأسماء يوم القيامة عند الله رجل تسمى ملك الأملاك
Bukhari narrated it in the Book of Manners (6206), and Muslim in the Book of Manners (2143:20), both through the route of Sufyan bin Uyayna, from Abu Zinad, from Araj, from Abu Hurairah, and he related it. The wording given is that of Muslim. The second narration of Bukhari (6205) came through the route of Shuayb, from Abu Zinad, with the same wording.Muslim said, Ashathi (whose name was Saeed bin Amr, and who was a teacher of Muslim) said that Sufyan said, "Like Shahan Shah." Ahmad bin Hanbal said, I asked Abu Amr about akhna, and he said, "It means most abased." The word "akhna" comes from khana, which means obscenity in speech. Akhna has also been explained as meaning most despicable, most immoral, and most repugnant. See Fath al-Bari (10/589).