BASTARD!!: Ankoku no Hakaishin - Kanzenban 01 Kakuchouban 2: Sheila-hime Oshaburi Chiryou

An alternative version of the scene from Bastard!! where Princess Sheila sucks the poison out of Dark Schneider's body.
Original Bastard!! author Kazushi Hagiwara released this as a Doujinshi expansion to Bastard!! Complete Edition Volume 1, which contains the original scene in question.
This is the second in his "Expansion Set" series of Bastard!! Doujinshi.