Imposing in his armor and with a deep, sonorous voice entirely unaffected by the helmet, Masamune most often concerns himself with armed conflict and generally favors those who are defending their loved ones and homes, though often the ideologies of the combatants matter less than if they comport themselves with honor.
Masamune carries a wooden flute of ebony, banded with gold, which can transform instantly into any weapon he desires. Seldom seen in cities, and most often seen on battlefields, he frequently counsels with one side or another prior to the battle, but never joins in the combat on either side. He will defend himself if attacked, and defeats enemies with blinding speed and martial prowess, seldom employing more violence than necessary, and killing only when left little other choice.
Those who encounter him in travel find him a generous host and a pleasant guest. Though not verbose, he upholds his side of conversations while frequently turning the focus back on those with whom he converses, genuinely interested in their lives. But while he visits with mortals he never stays. He does not sleep, and seldom stays more than a few hours before moving on, often playing tunes on his flute.