Not intended as a guide or a demonstration of skill, just a compilation of all the bosses and mini-bosses fought in this Ps2 game:

00:00 - Ranmaru Mori (first encounter)
01:15 - Brainstern (first encounter)
05:15 - Marcellus (first encounter)
07:20 - Heihachi Honda (first encounter)
08:55 - Genma Ranmaru Mori (second encounter)
11:35 - Gertrude / Guard Dog (first encounter)
13:45 - Doldows (mini-boss with Michele)
14:25 - Zmohs (mini-boss with Michele)
16:05 - Guildenstern
20:55 - Heihachi Honda (final encounter)
24:00 - Gertrude / Guard Dog (final encounter)
27:25 - Marcellus (final encounter / mini-boss)
29:00 - Vega Donna
31:55 - Brainstern (final encounter / mini-boss)
33:05 - Genma Ranmaru Mori (final encounter)
36:35 - Nobunaga Oda (with Jacques)
39:00 - Jacques Ending (cutscenes)
46:20 - Nobunaga Oda (with Samanosuke)
48:00 - Demon Genma Nobunaga (END BOSS)
52:20 - Samanosuke Ending (cutscenes)
58:05 - Onimusha 4 Teaser (Full Motion Video)


Enjoy.