How does Silvally's RKS System work?

Question

The plates are clear, but how would work with other items, like Berries or other held items?

Answer 1

RKS System is similar to Arceus' Multitype ability, where it'll change type depending on its held item (Arceus changes with Plates, while Silvally changes with Memories). If both hold items that are not the Plates/Memories respectively, they will be Pure-Normal-types.