Not much is known to who and what the Grandmaster looks like and the only ones who have faced her are her minions including the enforcers and her Anguis.
No one knows how powerful she can be as her society contradicts the beliefs of Septian Church; leading the two large groups on constant conflict. They also have different objectives for collecting ancient artifacts that includes all of the Sept-Terrion.
Campanella stands as her right hand man that currently holds the No. 0 rank Enforcer and has the same influence to the untold 1st Anguis. She recruited Arianrhod to her society after she was resurrected as she roamed the entire continent on her own.
The Grandmaster is still an unknown character towards the series as she never show her physical appearance. Neither her followers nor the history books tell the tale of her nationality and personality and seeking only to complete the Orpheus Final Plan.
The plan was subjected to be completed by various sub-plans that includes the Gospel Plan, Phantasmal Blaze Plan, and the latest: Great Twilight Plan.
Trails in the Sky the 3rd (+EVO)
In Star Door 14, the Grandmaster descends in the Celestial Globe when Campanella reports the aftermath of the Gospel Plan. Although grateful the plan was successful, she remorses over Weissmann's death and Leonhardt's sacrifice while the other Anguises plead not to.
Ao no Kiseki (+EVO)
- The leader's gender is speculated to be female according to the Ouroboros Report Drama CD.