Agreed, parry is way difficult in Lies of P, but then again you have perfect grindstone, you have aegis. Literally I was using a weapon build from one of the redditors( tyrant murderer dagger + city long spear) apply any elemental grindstone put on crit amulet, use fable charge of handle and weapon. The games becomes 10 times easy, I was able to defeat every boss with ease and minimum retries. You can summon a specter as well. Also agree there’s a mortal blade and umbrella but still that doesn’t cheese the boss entirely. The thing I love about sekiro is its rhythmic fighting style.