I cannot emphasize the countering in this game. Nothing makes you panic faster than seeing the symbol for an incoming devastating attack. Mikiri Counter is a MUST just for this reason. You can jump on an enemy's head when they perform a sweeping devastating attack to do posture damage equal to the Mikiri counter. Also, you can deflect these attacks! The only one I haven't been able to figure out are the devastating grabs, but most time you can just run out of grabbing distance.
I've beaten Sekiro three times, with the 3rd time being the MUCH shorter version. The "Shura" ending that is. Then I accidentally deleted my save files and had to start over from scratch because I want the achievements