Abu Dawud

Benefits and Issues:
The esteemed scholars have also declared it impermissible to be called or to call someone "Qadi al-Qudat" (Chief Judge) in the aforementioned manner.

Hadith Commentary:

The word "Akhna" means extremely worst, extremely vile. The worst and most vile name is that people call someone "King of Kings." Those who bear such names will be the worst people on the Day of Resurrection.

Hadith Commentary:
Vocabulary of the Hadith:
"Akhn'a" means "most abased":
The most humiliated,
according to Khalil.
"Afjar":
The worst,
disgraceful.

Benefits and Issues:
Imam Sufyan rahimahullah has translated "Malik al-Muluk" as "Shahan Shah,"
which is a Persian term,
the purpose of which is to clarify that not only is "Malik al-Muluk" the most abased and worst name,
but any name in any language that carries this meaning and concept holds the same ruling,
such as "Khaliq al-Khalq" (Creator of creation),
"Ahkam al-Hakimeen" (Most Just of judges),
"Sultan al-Salateen" (Sultan of sultans),
"Amir al-Umara" (Commander of commanders), and according to some, every name that is specific to Allah Ta'ala,
holds the same ruling,
such as "Jabbar" (Compeller),
"Qahhar" (Subduer),
"Rahman" (Most Merciful),
"Quddus" (Most Holy), etc.
Therefore, according to the Shari'ah, it is not permissible to adopt such names.

Benefit:
In this hadith, one of the attributes of Allah Ta'ala is mentioned, and that is «ملك الا ملاك», which in Urdu is called "Shahenshah" (Sovereign/King of Kings). That is, even the wealthiest person in the world should not be called "Shahenshah"; only Allah Ta'ala is the true Shahenshah. Furthermore, it is not permissible to interpret (ta'wil), liken (tashbih), specify the modality (takyeef), or deny (ta'til) the attributes of Allah Ta'ala.