Disclaimer: Spoilers up through Episode 25.
Jin was the better fighter - of that there was little doubt. Mugen was naturally skilled, had a grace and an energy of which Jin had never seen the like. But he was untrained, untested by the grueling agonies of bushido. Jin was poised, centered, capable. Jin was his master's prized student, and the only student capable of killing his master. He was the better swordsman, the better fighter.
He had watched Kariya easily parry Mugen's headstrong attacks, sidestepping every move, not bothering to seriously counter any strike. Mugen was being toyed with and probably knew it, but was unable to control his anger long enough to detach himself from the battle and reassess his strategy: a potentially fatal mistake.
Of course it had been the government the whole time - at every turn, every town, every run-down village, every checkpoint. The three had been let through, let go, to continue on their travels. It had been difficult enough so that suspicion wasn't aroused until it was too late. Each step bringing their watchers closer to that which they desired: Fuu's father, the samurai who smelled of sunflowers.
And now they had him, Seizou Kasumi. And now they had Fuu.
Mugen had to act. Quickly. "Go."
"Huh?" the pirate seemed confused. Jin might have been annoyed at his companion's thick-headedness if ninety-five percent of his concentration hadn't already been focused on his new opponent, teasing out ways to defeat him or at least to keep him from finishing his bloody orders long enough for Fuu to find some kind of safety.
Never taking his eyes from Kariya, Jin calmly stated, "I'll take care of this."
It was a samurai's goal to train, to study and master techniques and strategies, to pray: all of this with the intention of finding a lord to whom the warrior would be willing to give his life. Service not for service's sake - rather, for the sake of love. A lord to whom love was owed but was willingly given, for whom a warrior could not help but feel love. A samurai hoped to find a master who respected his soldier's lives, their skills, themselves, and who loved them in return.
Even as he trained, Jin hadn't truly believed he'd find a worthy lord - someone for whom he'd be willing to sacrifice and die. Even as he studied, Jin knew that his path was that of the ronin. Had he inherited the dojo, his eventual destiny might have been postponed. His master would have been bushido itself rather than a man who was fallible and petty, protected in a castle, hiding behind an insulating wall of centuries and class distinctions. Yet still Jin would have been alone with his swords.
Ever ready to stay and fight, Mugen quickly snapped, "You go."
Jin had known he had been awake the previous night, even if Fuu hadn't. While Jin alone would have been able to wake, rise, and return without waking his companions, Fuu was unskilled in stealth. While light on her feet and agile, while delicate and quiet (so long as she wasn't talking, or eating large quantities), it would have been impossible for her to move without both Jin and Mugen being aware. Her sadness had been palpable - forcing Jin from his light sleep and driving him to her, to some attempt at comforting her. Mugen, however, was not compelled to act. Or if he had, he'd respected Jin's place and feelings and had left them to their solitude and togetherness. Jin was thankful for that.
"Take care of Fuu."
Perhaps it was selfish, asking Mugen to go to her - preventing Mugen from the rush of heat and the elation of struggle. But Jin consoled himself with the knowledge that he didn't desire the glory of battle. He simply desired her alive - whole and healthy somewhere. Should he fall to Kariya's blade, Jin was certain he'd be able to buy her more time fighting and dying than if he left Mugen to the same fate and went for her, himself.
Understanding quickly crossed Mugen's face. "Don't die on me," he commanded as he ran down to the ferry landing. "You still need to fight me."
Mugen would find her and would protect her. Jin was sure.
He smiled briefly before turning his attention back to the government's assassin, before concentrating on the task at hand.
Jin mentally readied himself for the fight to come, for the death that very likely would follow and smiled inwardly. At last, he had found the lord he was willing to love and to die for. And she would live.