At the point he's talking to me, it's too late for stealth. Besides "Mace to the Face" has a much more personal touch. Alternatively, stab him with a dagger and yell "sic semper arrogantibus!"

For those that don't know: The assassination of Julius Caesar was done with daggers and accompanied by the declaration "Sic semper tyrannis", meaning "Such [will] always [happen to] tyrants". I've just replaced tyrannus with arrogans, which unsurprisingly is the ancestor for the modern "arrogant".

It should be noted that "tyrants" didn't quite share our contemporary definition and simply referred to autocratic rulers that had come to that power through non-constitutional means, and had no inherent valuation. A general staging a coup and usurping control could be a "good" tyrant if they were popular.

The Roman conspirators' concern wasn't necessarily with Caesar being a cruel warmonger, but with him twisting a tool designed for a short, crisis-time intervention to effectively supplant the Senate's and the ruling elites' control. The Republic was a useful system for those wealthy enough to afford entering a political career, so one of them holding all the power was understandably unpalatable.