In the origonal Devilman manga and Devilman:The Birth Welvath was a pretty young girl that Ryo Asuka had invited to his Black Sabbath party. Once Akira Fudo and Ryo have arrived at the party in Ryo's basement, Ryo goes on a rampage and attacks several partyers including the girl. Once enough blood had been spilt the guests started to transform starting with Welvath she attacked Akira but he starts to transform into Devilman and he crushes her head with his hand, he then moves onto the other demons .