Who wins the final duel between Fujiki Gennosuke and Irako Seigen of the Shigurui manga?

Answer 1

Fujiki circles round to Seigen's left. Seigen tracks Fujiki and swiftly turns to face him. Fujiki then brings his sword over his shoulder to perform Nagare. Fujiki swings the sword and releases his grip, causing the sword to fly out of his hand and land in front of Iku. Seigen, senses an attack, and lets fly with Mumyo Sakanagare, only to hit nothing. Fujiki then draws his wakizashi and attacks Seigen.

The two clash swords, and Fujiki uses the strength he developed in his arm and back muscles to carve through Seigen sword and into his body, cutting him down and leaving him dead.

The Daimyo then orders Fujiki to behead the fallen Seigen Irako.

Answer 2

It never says. However, fujiki's girl has a vision of him getting cut in half right before the fight. But it is still never said who wins.

Wrong! That may be how the anime starts/ends, but the MANGA, shows the end of their final duel. Fujiki wins. But you should really read the manga and see how everything unfolds leading up to it. It's a fantastic story.