Kihachi Okamoto's Sword of Doom is interesting in the ways it differs from a Kurosawa jidai-geki: unlike Kurosawa, he doesn't rely on lengthy, well-placed, well-choreographed medium shots to capture the swordfight's every movement (much as directors of classic Hollywood musicals rely on the same kind of shot to capture as much of the dancing as possible); his style is more impressionistic, more immersive, as if you're the one holding the sword, or receiving the stroke.
His tone is also darker, more nihilistic (darker than traditional Kurosawa--Kurosawa himself was already experimenting with more pessimistic material and more stylized filmmaking in Throne of Blood). Tatsuya Nakadai (a Kurosawa favorite) shows an intriguing combination of physical prowess and perpetual melancholy, his near-feminine eyelids drooping languidly over unseeing eyes (the effect is of someone too bored, or too deep into despair, to see what's in front of him). Interestingly enough, Toshiro Mifune (Kurosawa's most famous favorite) makes a cameo as a fencing teacher, and his assured stance, his rough-and-ready charisma--embodying the classic Kurosawa hero--makes for a vivid contrast to Nakadai's brooding anti-hero.
The film ends abruptly (SPOILERS); actually, it was meant to have a number of sequels, which were never made (it and a number of other films were based on Daibosatsu Toge (The Pass of the Great Buddha) a huge novel by Kaizan Nakazato). As is, that final freeze-frame is fascinating, unsettling--far more, I suspect, than any sequel could possibly be. The anti-hero played by Nakadai begins with the near-senseless killing of an old man (you might say Nakadai killed him because he asked for death), and ends with the character experiencing a psychotic episode, prompting a bloody showdown that ends with him surrounded by dozens of swordsmen inflicting great wounds from all sides, he in turn dealing out deadly blows in an apocalyptic massacre. The sense Okamoto gives you of a gradually accelerating fall, of a plummet from promising if cold-blooded swordsman to sociopathic assassin, is harrowing; that Okamoto halts that fall in mid-frame suggests a mere pause, suggests depths of nihilism and despair still untouched, yet about to be explored.