Messenger of Allah ﷺ said, "The most awful name in Allah's sight on the Day of Resurrection, will be (that of) a man calling himself Malik Al-Amlak (the king of kings).  

قَالَ رَسُولُ اللَّهِ ﷺ أَخْنَى الأَسْمَاءِ يَوْمَ الْقِيَامَةِ عِنْدَ اللَّهِ رَجُلٌ تَسَمَّى مَلِكَ الأَمْلاَكِ  

The Prophet ﷺ said, "The most awful (meanest) name in Allah's sight." Sufyan said more than once, "The most awful (meanest) name in Allah's sight is (that of) a man calling himself king of kings." Sufyan said, "Somebody else (i.e. other than Abu Az-Zinad, a sub-narrator) says: What is meant by 'The king of kings' is 'Shahan Shah.,"  

أَخْنَعُ اسْمٍ عِنْدَ اللَّهِ وَقَالَ سُفْيَانُ غَيْرَ مَرَّةٍ أَخْنَعُ الأَسْمَاءِ عِنْدَ اللَّهِ رَجُلٌ تَسَمَّى بِمَلِكِ الأَمْلاَكِ قَالَ سُفْيَانُ يَقُولُ غَيْرُهُ تَفْسِيرُهُ شَاهَانْ شَاهْ