Which Pokémon has the exclusive ability 'RKS System'?

Silvally has the exclusive ability RKS System. This ability allows Silvally to change its type when it holds a Memory item, making it the completed form of the Type: Null evolutionary line.

Type: Null was created as an artificial Pokémon designed to reproduce the adaptability of the Legendary Pokémon. Its restrictive mask suppresses its biological potential and helps control its power. When Type: Null forms a strong bond with its Trainer, it can evolve into Silvally, shedding the mask and gaining access to RKS System.

RKS System is a major part of Silvally’s identity. The held Memory determines its type—for example, a Water Memory makes Silvally Water-type, while a Fairy Memory makes it Fairy-type. Its signature move, Multi-Attack, also changes type to match the Memory it holds.

A common mix-up is choosing Type: Null because it is Silvally’s predecessor. However, Type: Null has Battle Armor, not RKS System. Arceus can also change type through its Plates, but that is a different ability and does not make Arceus the Pokémon with RKS System.