Sekiro: 10 Helpful Tips & Tricks To Defeat The Final Boss
5. A Few Additional "Goomba Stomps"
Another brilliantly simple tip that will help you retain a lot of health as well as allowing you a couple of crafty hits of your own.
What's surprising is whilst watching others play they tend to avoid this.
In round three (Phase Two of Isshin when he breaks out the spear and the gun) he likes to do a charged attack. This spear swing does an insane amount of damage and covers a very wide area. What you do next depends on how far from him you are.
If you're at a great distance just stay there or back away some more and heal or use an item etc.
If you're at medium to close range run in and jump on his head, and that's it. The game cheats a bit by not flashing up the red unblockable attack symbol to indicate you can do this, but you can.
Mario stomp him then slash him a couple of times. Easy.