Not a hard feat to accomplish as long as your bodycount is above zero
Isn't this kind of hypocritical since Kizaru couldn't kill Bonney, Franky, Sanji, Luffy, Luffy again, Zoro (pre ts mind you), Sentomaru, Marco, Drake (pre ts), Urouge (pre ts), Apoo (pre ts), Hawkins (pre ts), etc.
And if we count attacks that were blocked or missed (like the image you posted does), then we can say he failed to kill Luffy yet again, as well as Atlas, Franky, Sanji, and Vegapunk.
Anyway, Kizaru didn't accomplish his mission. Saturn had to do it for him.