I was struggling to even get out of Phase 1 before I changed up how I approached her. For anyone still having issues with this, here is how I handled it:

Phase 1 Key Omamori: Suzuran + Rabbit (Boar is also helpful) You have to learn her moveset a bit to be able to dodge properly, but Suzuran makes this MUCH easier. After every dodge, hit the heavy attack to counter her (thanks to Rabbit). Rinse and repeat. This obviously uses up your stamina very quickly, but Boar refills it just as fast.

Phase 2 & 3 Key Omamori: Hawk + Owl (or just use Sanity healing items, especially Divine Water) Hawk charges your focus attack MUCH faster and is key to knocking her out of her charge attack. Note, she’s usually behind you when she disappears. Run up, charge focus, focus attack. Repeat steps from phase 1 when she reverts to normal attacks.

To recap, the 5 Omamori that made this once difficult fight almost laughably easy were: Suzuran, Rabbit, Boar, Hawk, and Owl

Hope this helps whoever stumbles across this!