>>24980180Things that counter AyaP in the base game are hard to find (she has a lot of checks like FutoS), but the expansion neuters her a lot. Small Bit can be equipped on any relatively defensive puppet to screw her over, even in the base game, and some of the bulkier focus walls can equip this and render her half-dead right off the bat. Things that get Will-O-Wisp, Confinement, or other Darkness/Paralysis-inducing attacks can also shut her down, so stuff like ParseeD can neuter her if she decides to stay in.
In the expansion, she's hard-countered by CirnoE and anyone else with the ability Wariness (nulls damage from attacks with under 50 BP), MomijiE, and HecatiaE, among others. Nether/Warp types like SekibankiE can switch in on either of her STABs and do heavy damage if they have enough focus defense to withstand a Spirit Stone Jig. KikuriE can easily weather one or two attacks and retaliate with Revolving Illusion. Some of the new bulkier Wind-types like MokouE can switch in on a Fighting or Earth-type attack and force Aya out by threatening her with Wind attacks.
Some of these are checks, but the expansion hasn't been kind to her. And these are just the ones I know off the top of my head.