This movie tries to be an adaptation of the original manga by adapting the whole story while at the same attempts to put Takashi Miike's original twist. It fails at both.

It should've been obvious that you can't adapt manga spanning 207 chapters long to 141 minutes movie. To compensate this, Takashi cuts story arcs and make his own plot direction, which is normal and can actually be done well. However he still attempts to give (multiple) nod(s) to the original manga, which makes the movie ended up as nerd-fest references but jumbled mess of plot.

Characters come and go. Itto-ryu becomes villains of the week. Some characters remain alive as a nod to the manga but left unseen/unexplained [spoiler](i.e. Magatsu)[/spoiler]. Even the main protagonists and villain (Manji, Rin, and Kagehisa) aren't given enough time to explore their relationship and quest(s) for revenge. Takashi's attempt at portraying dialogues between Rin and Kagehisa ended up as merely manga reference that wasted 5 minutes rather than taking that as a plot point. Shira's appearance at the end come out of nowhere, interfering with the original plot Takashi has been building up, which seems to serve nothing but another reference to the manga.

Takashi actually cuts and wraps at the important points in the manga where he tried to develop his own story. But he seemed to hesitate frequently in continuing to develop his own story. Philosophical banter between characters, especially between Manji and Shizuma Eiku which seems to be adapted straight out of the manga, felt hollow. The ending feel forced with typical shonen manga-like resolution. He should have focused on the original plot he intended to develop, or, if he wanted to adapt faithfully to the manga, should have taken one small arc instead of compressing all those at one stroke.

The fights are well choreographed as per Takashi usual, especially in Kagehisa fights in which the weight of his weapon can be felt by the audience. This is no small feat considering Rurouni Kenshin's adaptation, with Sanosuke looked like swinging plastic sword. Casts are great. However they can't save Takashi's _Blade of the Immortal_ from measly, boring 2 hours run.