Carl solemnly removed the greatsword from the rack behind him and set it aside on the deck. Although he usually carried it, he knew this duel with Hawkeye required a different approach. Hawkeye watched and remarked, "Why not bring your sword? You should know that I do not mind if you use your Devil Fruit abilities, as long as you use a sword". Carl shook his head firmly, explaining that he used the giant blade primarily for flying, sneak attacks, and clearing out fodder, and that carrying it during a fair duel would be nothing more than a burden. After finishing his sentence, he jumped onto the desert island, and Hawkeye followed shortly after.
The two chose an open area to confront each other, while the crew on the Thousand Sunny watched with intense excitement. Robin looked worried, fearing that Carl might be seriously injured against the world's number one swordsman, though Marie silently held her hand to comfort her. On the island, Carl drew his Sandai Kitetsu and took an offensive stance, while Hawkeye solemnly pulled out his black blade, Yoru.
As Carl flashed forward to strike at Hawkeye's waist, Hawkeye parried, only to find that Carl had disappeared in a blur. When Carl reappeared above Hawkeye's head, his blade point was aimed directly at the swordsman's forehead. Hawkeye slashed upward with Yoru, but Carl had already vanished again, leaving only an afterimage as Yoru cut through empty space.
Hawkeye was startled by the speed, but as he recovered, Carl appeared in front of him and launched a slash toward his face. Hawkeye dodged in a hurry, though the corner of his black coat was sliced off. For the next few moments, Carl pressed the advantage with rapid-fire sword techniques, but Hawkeye, as the greatest swordsman in the world, quickly adapted. Once he adjusted to the rhythm, Hawkeye became calm, easily deciphering and parrying Carl's moves.
On the ship, Zoro, Law, Tashigi, Brook, and Kaku watched intently. When Tashigi asked why they weren't using Haki, Zoro explained that this was a trial stage, with both men using simple sword moves to test their fundamental skill. Zoro noted that Carl was using this opportunity to hone his own swordsmanship and, more importantly, to give the crew a lesson in combat.
Carl began to blend his own wild style with the techniques he had observed from Zoro, Law, Tashigi, Brook, Vista, and Rayleigh. As Carl's moves shifted from fierce to delicate, Hawkeye recognized the intent and switched from defense to offense, forcing Carl into a desperate position. Carl eventually pulled out his second blade, Obsidian, to keep pace. While Carl managed to resolve many of Hawkeye's attacks, it was clear to any observer that he was losing in pure swordsmanship.
After two hours of intense combat, Carl was covered in scars, and Hawkeye appeared slightly disheveled. Carl took a deep breath, and his aura shifted as he began to coat his blades in Armament Haki, while his Conqueror's Haki flickered around his brow.
"Is it finally time to go all out? Well, the warm-up should be over!" Hawkeye exclaimed, his fighting spirit surging.
Hawkeye rushed forward, his hands coated in dense Armament Haki. He unleashed a massive flying slash that threatened to tear the very space in half. Carl did not dodge, instead meeting the attack with two simultaneous slashes of his own, crackling with black lightning.
Boom! The two slashes collided in mid-air, exploding instantly. The shockwave ripped through the deserted island, shattering the ground into countless fragments and sending the local beasts fleeing in terror.