Succubus Nostrum is one of the magical potions described in Monster Girl Encyclopedia World Guide III: Sabbath Grimoire.
Guide Book Entry
Pure condensed "Succubus" mana, made into a liquid potion. It has a bewitching hue like a mixture of pink and purple. Within the body of all monsters dwells the mana of Succubi that brings the beautiful figure of a woman and nature of inma. In other words, "Succubus Nostrum" is an existence that can be said to be the crystallization of the power of inma brought to all monsters from the mamono lord. By drinking "Succubus Nostrum", monsters can raise their own inma power and activate their monster mana. As the devilish charm that resides in that beauty gets stronger, nymphomancy, including "seduction spell", will exhibit a higher strength. Also, as a result of rapidly enhancing the power of erosion possessed by monster mana, monsters with "the power to make human women become monsters" will be able to transform women more easily, and change them into even lewder monsters.
When "Succubus Nostrum" is given to humans to drink, it brings instant incubization for men, and instant monsterization to women. Also, due to the thickness of the mana contained, it also exerts high effects on things besides humans. If you dribble it onto a plant, it will transform into a monster realm plant, and if mixed with a potion, it will show a lewd effect no matter which one it is. By giving it to animals such as cats and dogs, monsters such as "Cu Sith" and "Cait Sith" are produced, and if you dribble it onto objects, even artifact spirits such as "Chochin-Obake" and "Karakasa-Obake".