People are still calling it a souls like jfc. It's a Ninja Gaiden+Diablo mix with some souls elements. Nothing in this game screams "souls formula" and if you play it like a souls game you get punished hard. It's like saying Sekiro is a souls like, which it isn't.
The only thing Nioh has in common with Souls is the bonfire mechanic and how you level up a character... that's it. Souls has no levels. Souls has no random loot (with tons of effects on it). Souls has no endgame progression like Nioh. Souls combat is based around stamina management, which isn't the case for Nioh's (that's what ki-pulse/flux is for).
Nioh's whole gameplay loop is comparable to an action RPG like Diablo and scratches a completely different itch, this is also why you see lots of people who couldn't warm up to Dark Souls ending up liking Nioh.
If you have to play a game five times for one of the systems to start making sense... there is a problem.
You don't play the game 5 times to progress into higher difficulties. That's not how the game works, progressing into higher difficulties is a matter of replaying whatever levels you want, you just need to fulfill certain requirements to progress into a higher difficulty. You simply keep on doing what you've been doing before, you just get new things to do on higher difficulties because new systems get unlocked and gear gets more complex.
It's again pretty similar to an ARPG like Diablo and the first playthrough is there to help you learn the basic mechanics of the game (mainly ki pulse and playing aggressively instead of playing it like Souls).