Raven Branwen and Mega Absol

In a FanFiction crossover of "Pokémon X RWBY," Raven is Qrow's sister. Years ago, she now works as a Pokémon researcher who was obsessed with this concept known as the "Dream World," an alternate dimension that only Pokémon can access via dreams. Raven was so obsessed with this concept that she would spend days in a row doing nothing but attempting to get into the Dream World and learn what Pokémon do there, and the supposed nightmare Pokémon that lives in this dimension. 

Shortly after Yang's birth, Raven went right back to her research, and then mysteriously disappeared. No one knows what became of Raven; not even if she's still alive.

In "Mega-Ventures of Remnant," Raven's signature Pokémon is her Absol (also in Mega), and her Key Stone is "Mega Amulet."