I opened a few similar threads in the past, but I have a few more ideas, and I think that reworking the pk would be extremely important to help the game.

The peacekeeper is in a very weird position. She is very safe, just mixing zones and left heavies into guardbreaks is enough to stop basically any combo (or at least make the opponent play on your terms). Her neutral light parry punish is still the most damaging one in the game (heavy+bleed, 48 damage), which makes her an incredibly effective turtle, but at the same time, she is not able to be really offensive. She lacks any unblockables, which obviously hinders her ability to attack, her heavy attacks are surprisingly slow, and while you can create interesting mixups with her, you can clearly feel that you are in a disadvantage compared to the "optimal" playstyle. Her zone can't be even worked into mixups because it takes the full stamina bar to feint the second, free parry attack, so if you want to do more than spamming zone attacks, you can't use it at all. Her oos back dodge is also unfair, but I know that you are working on that.

Rework idea:

Her zone attack needs two changes. First, remove the second part. I can barely think of any real use for that, it's always a free parry. Second, nerf down the damage, between 5 and 10. 20 damage is too much for a 400 ms attack, it should work mainly as an interrupt tool, not as the main damage tool.

The dagger follow up should be removed. The pk shouldn't deal 48 damage just for landing a heavy, and always using the confirmed hit after a succesful heavy seriously slows down the fights and further limits her mixup potential. Some of the damage could be worked into the heavies and dodge heavies.

What the peacekeeper desperately needs is an unblockable. I wouldn't give her more than one, but her inability to punish exhausted opponents is very frustrating. A three heavy chain with an unblockable finisher would be nice. Her dodge attacks should also work as chain starters, she should have the ability to dodge out from any heavy, and her dagger cancels should work from any direction. I don't know that her heavy softfeints into guardbreaks should or shouldn't work during midchain heavies- the shaman's do, but I never felt any need for them, and that would be broken for the pk.

Some bleed bonus effect would also be nice, but not as strong as the shaman or nobushi has, just something little to make it more useful (like increased block damage or a very small stamina recovery on hit).