This is a special shout-out to @Magpie as my way of saying thanks for all the help and support she's given me since I first joined Pokécharms. I hope I didn't butcher your favorite pokémon by Nega-Mega evolving it.
Anyway, when trying to think of a Nega-Mega evolution for Manectric, I was at first trying to think of something related to this pokémon's concept origin (wolves), as well as British &/or European folklore to make it more relatable to Magpie. Eventually, I decided to model this design off of a werewolf since the wild and messy fur they normally have would go perfect with Manectric's mane. I also added some references to the Japanese Raijū (another one of its references) such as the thick eyebrows and elongated claws.
Since Nega-Mega Manectric is mostly based on a werewolf, I decided to make it part Dark type since they're usually seen as monsters. Plus, the lime green bursts of light around its mane and claws are meant to be sparks of its electricity since the color Lime Green is usually associated with evil in cartoons