• English / United States: Diana
• Japanese / Japan: ダイアナ
• Japanese (Romanized) / Japan: Diana
• Japanese (TL) / Japan: Diana

Diana is Liko's grandmother. She currently lives in the Galar region at an old castle. She gave Liko her mysterious pendant just before she started school in Kanto. Unbeknownst to Diana, it turned out that the pendant was the mysterious Pokémon Liko's Terapagos (Pagogo).

Since a young age, she always wanted to be an adventurer as she was influenced by the pendant and the records of Lucius. She is impatient according to Liko and eats out of tin cans as it saves time from cleaning up.

She traveled the world and investigated the adventurer Lucius but gave up 30 years prior to her meeting with the Rising Volt Tacklers as she couldn't find any trace of Lucius.

She was an old friend of Hamber and he came to visit her one day as he said he was going to introduce her to a person that could help her with her adventures but it turned out that he was involved with the Explorers organization and they wanted her pendant.