I have played hundreds of single player games but never touched the Onimusha games. So i can't compare this adaptation on how faithful it is to the Capcom games. So coming unfamiliar to the lore and story i am generally pleasantly surprised about how good the anime turned out with just a few minor flaws.
Overall i liked this show way more than Castlevania Nocturne which i watched recently too. And the reasons are many. This show had extremely well written dialogues, the pacing was right and the protagonist was very intriguing and grounded. The art style was also fine to me. Nothing spectacular but i didn't have a problem with it at all. It felt unique on its own. It was like watching different sets of paintings. Like it was hand drawn art style and animation. Different doesn't mean bad. The rest of the characters besides Musashi were also quite good, with each one having different personality, motive and skills. The fantasy elements in the show was also done in a way that it didn't feel bloated and it balanced the realistic action fights very well. The action felt 90% on point with only in a few occasions becoming over the top. But i also have to point out some flaws too.
First flaw for me was that the villains were not interesting. The reason is that half of them either didn't have clear motives and backstories for them to care about, or their characters were simply very straightforward and one dimensional. Second flaw for me was that the show didn't took the time to explain some of the lore and mythical elements such as the gauntlet's origins, who made it and when, how Musashi knows about it to begin with and wanted it so badly that he fought countless men risking his life to obtain it and how the monks gave it so easily based on how valuable it was. I would also have liked to see the history and the conflict from flashbacks of the gods of this universe (Oni Vs Genma) and what each one represents with their different powers. A backstory through flashbacks of Musashi when he was young fighting through duels and wars, his training and upbringing and how he became the best swordsman would have been cool to see too, even if it was for a couple of minutes. This would be such a cool idea for a prequel series without having to rely on fantasy elements and the show would work just as good or better in my opinion because Musashi was a very well written character with a great voice actor.
Overall i am satisfied with the show, because it had most of the things i asked for. Great action, art style, voice acting, writing and pacing all amazing with only flaws being the villains and the very little explanation of the fantasy elements, powers and gods of this world. Feudal Japan is such a cool concept to adapt into live action, anime or games that i really hope the trend continues. I look forward to the Shogun live action Remake TV show, Ghost of Tsusima movie but most above all i look forward for the Sekiro anime adaptation that was announced just a couple of months ago. It is very similar in concept to Onimusha . If it has that kind of passion like these creators showed in this show with just higher production values it can easily be one of the greatest animes of all time. The Fromsoftware game that won Game of the year 2019 is still considered one of the greatest action games of all time and one of my favorite games.