That doesn't look anything like Ninja Gaiden though. It's way slower and focuses more on 1 on 1 combat. The guy's in that video still being careful and methodical. There's no need for baiting attacks in Ninja Gaiden most of the time.
NG often has you fight 5+ enemies at the same time. That's just not possible in Nioh because your mobility is very limited compared to NG.
For clarification, nobody is saying this game is literally like Ninja gaiden in every way, but it carries over plenty of elements from Team Ninja's previous series to be notable.
You can fight many enemies at a time in NIOH if you want, but you have to be good to take them out. Also, you DO have to be methodical in blocking and dodging and planning your attacks in Ninja Gaiden as well, but NG like this game is about exploiting your opponents guard.
In NG all i do when enemies shrink back is expose their guard so i can go in with an Izuna drop.
It feels like Nioh is as if Team ninja went in specifically in mind with building on the NG guard break tying it to a stamina mechanic.
Trying to say this game is a souls game is doing a disservice to it