"The strongest slash in the world".

When Aokiji froze the two tsunami that Whitebeard caused, Mihawk was one of the first to attack, wishing to measure his strength against Whitebeard. His attack, "Sekai Ichi no Zangeki" (the strongest slash in the world), was stopped by Jozu. Mihawk's attack didn't damage Jozu at all and it is unknown as whether or not Mihawk has an attack that could cut through diamond yet.[15]

He shows slight amusement upon Luffy's arrival at Marineford, remarking that the Straw Hat pirate never failed to make things interesting. When Sengoku reveals the fact that Dragon is Luffy's father, he only comments that such a revelation isn't really surprising. When Luffy manages to break through the line, Mihawk goes to meet him head on. He addresses an apology to Shanks, saying he won't hold back and wonders if fate will save Luffy from his black sword.[16]

His fight with Luffy mostly consisted of various long-range sword-slash attacks, the first of which attacked Luffy from long range and damaged him, and one which was strong enough to cut off the head of one of the frozen tsunami and send it crashing down upon the battlefield. For a brief moment of time Mihawk consistently launched slashes to Luffy, who managed to execute mostly-successful dodging. However, Luffy could not attack, was losing distance, and was having great trouble even simply dodging. Luffy grabbed Buggy and used him as a shield against Mihawk's attacks. Buggy, enraged, launched a Muggy Ball at Mihawk, who effortlessly deflects it back at Buggy. As Buggy took the hit, Luffy dashed past Mihawk. However, the Shichibukai still had his sights on Luffy.