Rotom Zukan  

Rotom Pokédex, ロトム図鑑

The Rotom Dex, also known as the Rotom Pokédex, is a unique electronic device found in Alola that enhances the traditional Pokédex. Despite being rare even in its own region, Ash received this special Pokédex from Professor Kukui during The Guardians Challenge! It was initially empty until SM003 when Kukui completed it by having a Rotom enter the device and transform into the Rotom Pokédex Form. Since then, it has registered Ash as its user and follows him around. As an advanced self-learning AI similar to a human, Rotom claims to learn from new information about Pokémon and updates itself accordingly. When it discovers a new species, it displays their details and gets close to the Pokémon to verify the accuracy of the data. However, this habit often leads to conflicts with the Pokémon, resulting in attacks on Rotom. Despite its friendly demeanor towards Ash and his friends, Rotom shows an aversion to Sophocles whenever he tries to study it. After inhabiting the Pokédex, Rotom appears to have lost all combat functions and is unable to utilize any moves.