Zassler is an extremely old and thin man, with long, white eyebrows, going down to his chest
When the Radiant Church captured him and was escorting him towards their base, Linley intervened freeing both Zassler and killing his capturers. After being freed, he requests Linley's aid in freeing two other captives of the Radiant Church, the sisters Rebecca and Leena. Afterwards, Zassler decided to join Linley in his conquest against the Radiant Church. He is also the teacher of Rebecca and Leena in Necromancy. He became a Demigod by fusing with a death Divine Spark given to him by Linley.