Traveling through the world of pirates, Rosen becomes a student of Zephyr's class. He starts with a weapon fruit and also obtains the full level of comprehension talent.

With his extraordinary understanding, he created many extraordinary abilities.

"Your comprehension is extraordinary. Through visualization and self-realization, combined with the superhuman weapon fruit, you have mastered a unique skill: Senbonzakura."

"Your comprehension is extraordinary. Through visualization and self-realization, combined with the superhuman weapon fruit, you have mastered a unique skill: Flowing Blade Jakka."

"Your comprehension is extraordinary. Through visualization and self-realization, combined with the superhuman weapon fruit, you have mastered a unique skill: Slashing the Moon."

…

Warring States: He is the navy king who reigns over the world.

Shanks: His Haki can crush the Great Pirate Era.

Five Elder Stars: His sword can cut off the Great Pirate Era and end the rule of the World Government.