Crocodile

Sir Crocodile, also known as the "Desert King," is a former president of the notorious Baroque Works criminal organization. He operated under the alias "Mr. 0" while his vice-president and partner, Nico Robin, went by the name "Miss All Sunday." He is the main antagonist of the Arabasta Arc and the overarching Arabasta Saga, and later appears as a supporting character in the Impel Down and Marineford Arcs. Crocodile is a formidable foe and is one of the most significant adversaries in the series. He was the first enemy to hand Luffy a crushing defeat. Initially, Crocodile was one of the Seven Warlords of the Sea, but he lost his title after trying to take over the Arabasta Kingdom.

Luffy frees Crocodile from Impel Down in exchange for his assistance in rescuing his brother, and Crocodile joins the Summit War on the side of Luffy and the Whitebeard Pirates. Following the war, Crocodile establishes the Cross Guild in the New World with Dracule Mihawk, another former Warlord. The organization's figurehead is Buggy, a current member of the Four Emperors, who serves as a distraction to attract unwanted attention away from the guild's true leaders. Crocodile's powers stem from the Suna Suna no Mi, a Logia-type Devil Fruit that allows him to create, control, and transform his body into sand. He has honed his ability to the point of perfection and can reflexively turn into sand if attacked. In a desert or sandy area, he is nearly invincible and can create sandstorms, quicksand, and bladed weapons. He can also absorb all moisture from living and non-living objects via his right hand, which causes dehydration and destruction. However, this technique does not work on metallic substances, and any moisture that comes into contact with his body immediately reverts to a solid form.

Dracule Mihawk

Dracule "Hawk Eyes" Mihawk, a renowned pirate, is famously known as the "Strongest Swordsman in the World." He was once a member of the Seven Warlords of the Sea and was the first to be introduced to the audience. Mihawk was also known as the "Marine Hunter" due to his reputation as the rival of Shanks, one of the Four Emperors. He currently resides on Kuraigana Island and served as Roronoa Zoro's swordsmanship trainer during the two-year timeskip. Mihawk, along with his former Warlord peer Crocodile, founded the Cross Guild, with Buggy acting as the organization's figurehead leader. Zoro considers Mihawk as the ultimate obstacle in his quest to become the world's strongest swordsman, given his status and title.

Mihawk played a supporting antagonist role in the Baratie Arc and was a significant antagonist in the Marineford Arc, where he participated in the Summit War of Marineford on the side of the Marines, along with most of the other Warlords of the Sea. Mihawk's swordsmanship skill is unparalleled, earning him the title of the "Strongest Swordsman in the World." His mastery in swordsmanship even surpasses his former rival Shanks, one of the Four Emperors of the Sea. He effortlessly defeated Zoro with a single knife, despite Zoro being a renowned swordsman all over the East Blue, two years before. Mihawk's swordsmanship is extremely versatile; he can create immensely powerful compressed air slashes that are able to destroy gigantic ships and enormous icebergs from great distances by using the "Strong Blade" swordsmanship, and can deflect the course of bullets with masterful and graceful precision using the "Gentle Blade" swordsmanship. He is also able to cut through steel with extreme ease and precision, as demonstrated with the steel-bodied Mr. 1, whom even Zoro struggled to defeat. Mihawk is also a talented teacher, as shown by Zoro's significant improvement in training under him for two years, which is more than the dojo had taught him in the many years he had trained there. Zoro himself admitted that even after training with Mihawk, he is still not anywhere near his level of skill as a swordsman, further attesting to Mihawk's combat and fighting prowess. Mihawk is known as the "Strongest Swordsman in the World" because of his unparalleled skill with a sword. His vast mastery in swordsmanship even surpasses the skill level of his former rival Shanks, one of the Four Emperors of the Sea. He was also able to effortlessly defeat Zoro, a swordsman who is renowned all over the East Blue, two years prior with a single knife. Mihawk's swordsmanship is extremely versatile; he can create immensely powerful compressed air slashes that are able to destroy gigantic ships and enormous icebergs from great distances by using the "Strong Blade" swordsmanship, and can deflect the course of bullets with masterful and graceful precision using the "Gentle Blade" swordsmanship. He is also able to cut through steel with extreme ease and precision, as demonstrated with the steel-bodied Mr. 1, whom even Zoro struggled to defeat. Mihawk is also a talented teacher, as shown by Zoro's significant improvement in training under him for two years, which is more than the dojo had taught him in the many years he had trained there. Zoro himself admitted that even after training with Mihawk, he is still not anywhere near his level of skill as a swordsman, further attesting to Mihawk's combat and fighting prowess. He was later seen together with Crocodile on Karai Bari Island with a beat up Buggy, due to the latter not only being recognized in the world as an Emperor but also as the leader of their new organization. Although feeling greatly insulted, he claimed that Buggy taking all the heat as a figurehead may not be the worst idea. He further added that he was not interested in the title of Emperor, preferring to live peacefully and that they could always get rid of Buggy when the need arises, which Crocodile agreed to Mihawk's suggestion. He was then, together with Crocodile, introduced by Buggy to his followers.