Yaelen

Yaelen is a Gengar from Kanto, born in Lavender Town and spending a lot of her time exploring the world outside of the secluded little place. Much like Shivok, she's a Shiny Pokemon, and as such her physical strength is not great- and Gengar don't have great physical strength to begin with. Yaelen's arms have roughly the tensile strength of cooked linguini, but that doesn't stop her- her magic ability is naturally pretty high, so she can use all sorts of special moves to make up for her awful physical strength.

Like most Gengar she's a mischievous soul, loving to cause trouble wherever she goes, but in her non-Mega form, she certainly has restraint, rarely doing anything that could actually hurt someone. She's kept in her non-Mega form most of the time by her friends, as she's much less...er, stable when Mega.