In Atelier Iris 2, there is a Dark Mana named Lutanus who works as the library organizer in the Eden Temple.
Plua is a dignified, quiet and shy young woman, although with great power. She is sensitive, but she is kind. Aware of her powers, she only made pact with powerful alchemists,
In Eternal Mana, her ability is to gather enemies around the player, although this may not always work.
Atelier Iris 2
Plua is one of so many Manas that lost her Holy Ground, the Moon Tower. Once the Moon Tower reappeared, Viese went there to make a pact with her, however Plua refuses, saying that she could only hurt others. Confused, Viese than asked Lutanus. Lutanus then told Viese the whole story: Plua was once contracted to an alchemist. Excited, she overused her powers and accidentaly injured the alchemist. The alchemist got very angry at her, Plua ever since then refused to make any other pact and confides herself in Moon Tower. Viese then attempted to persuade Plua into making pact with her, saying that it is not Plua's fault that she injured the alchemist. Moved by Viese's acceptance, she then agreed in making the pact. The player is then bestowed with Dark Gem.
Atelier Iris 3
Plua; Virgin of Darkness, is Edge's Blades Master, obtained after defeating her in a Mana Boss Battle. Edge's blade when in this form is a kunai, resembling ninja which prioritize speed. While using her as Blades Master, Edge gains an outstanding boost in his speed, however his attack power drops greatly to compesate for his speed. His main point while using this Blades Master that he's as quick as Nell, or even quicker, enabling him to act most often and first.