Zolgear is the main antagonist of the first season of The Testament of Sister New Devil and the one who is responsible for the deaths of Mio foster parents.


At some point he created Zest and plans to overthrow Leohart in order to become the new demon lord by hiding a secret weapon in the form of his mansion and Zolgear murdered Mio Naruse's foster parents and sends both Zest and Lars as her observers but unknown to him Lars is secretly seeking revenge due to Mio's foster parents being the people who raised Lars.

Eventually he sends out Valgar to kidnap Mio but Valgar is killed by members of the Hero clan.

He then used Sheera as a hostage and have Maria kidnap Mio but Basara figures this plan out and have Lars rescue Sheera and used a decoy to fool Zest.