Sekiro: Shadow die twice, holds strong at 90 on Opencritic based on 111 reviewers. GotY?

[Angelus]

John2290 said:

Angelus said:
The key to Isshin during phase 2, and 3 (though 3 is mostly lightning reversals), is to stay up in his face, and deflect him to death. You barely even have to attack him at this point. Just deflect all his regular hits, and mikiri counter him when he thrusts (which he will do all the time). You can get a few hits in here and there, but you don't need to do much offensively. He'll more or less tire himself out on you.

It would be impossible to keep close to him in phase 3 because of the lightning. At least for me as I can't counter it. 

It's really not very hard to counter, as it's got a relatively slow, long wind up. Just jump up shortly before he shoots it at you, and then reverse it before you touch the ground.