Used any weed and feed product in the grass? It looks like weed killer damage. The grass is way too close to the plant.

Tomorrow's plan was to remove the rest of the grass around it. I bet that's the problem! We only bought the house in July and from the look of it he used Weed & Feed every ten minutes. Honestly. Not a single plant in the whole yard that was anything but a blade of grass. I'll move the rest of the grass and sod away, do you think it'll figure itself out? It's way ahead of the other peonies I planted at the same time. :/

Only time will tell. I would not count on it surviving with all of that damage. Only thing two things that I could suggest would be dig it up now and remove all of the leaves and top growth then replant in another area. Second is remove all top growth and hope new growth emerges. With that type of damage I would not plant anything in that area that has broad leaves for at least a year or perhaps longer. For now raised beds and large flower pots are your friends.

I see some broadleaf in the pictures, so it should not be too bad and if your other peonies are surviving as well... When did you plant it? If just recently you can move it without too much hassle. Just be careful. Good idea to change the soil before you plant it somewhere else if you are not sure about weed products which were used. Just make the hole as big as possible and get the proper soil, not some pot variety only...those ones are too moisture-absorbent and peony do not like wet feet generally.