Can you think of any leaders/rulers, past or present, who possessed these qualities?
The qualities actually mentioned in the poem are physical characteristics, such as a "frown, and wrinkled lip, and sneer of cold command," and the attitude conveyed by the quote "My name is Ozymandias, king of kings: Look on my works, ye Mighty, and despair!"
There are many past and present leaders who could be described has having these qualities. Adolf Hitler of Germany, Idi Amin of Uganda, Joseph Stalin of Russia, and Saddam Hussein of Iraq are all deceased political leaders who would concur with the domineering attitude represented in the statue. President Omar al-Bashir of Sudan might be a contemporary political leader who would agree with the philosophy of Ozymandias - his leadership role in the genocide in Darfur seems to have many of the characteristics of actions taken by the other leaders mentioned above.