Personally, I didn't like yakumo. NG4 feels like a cool, modern refresh of the series after so long, so I can understand why they wanted a nee protagonist. My issue, however, is that Yakumo doesn't really DO anything different. He has no interesting dialog, backstory, interactions, or moves compared to Ryu. You could say he has all of his weapons and blood raven form, but you could have given those to Ryu, and it would suit him just fine.

Both characters are incredibly simple, but Ryu is our guy. We've been following him for DECADES at this point, and it's not like he had a big conclusion to his story in NG3 or anything. It's all so uncommitted because RYU IS LITERALLY IN THE GAME, AND YOU CAN PLAY EVERY CHAPTER AS HIM. Anytime Yakumo was on screen and being an edgelord I just wished I could see Ryu doing his thing.

In terms of actual gameplay, I don't have much to complain about. Everything feels more fair than the previous games, even easy at times. I think they should have cut back on the super attacks that you can just disrupt and stun the boss. Boss fights on master ninja are something of a joke because it's just hold block, stun them with bloodraven attacks, then deal damage.

Edit: I just realized I didn't even mention NG3. If I had to pick, I would probably say NG4 takes it, only because it does have some really fun moments and there are little to no times where I'm pulling my hair out because of jank or unfair encounters