Hydryst Marcellinus

Hydryst Marcellinus was a famous mage and Goetic Theorist of Ozlith who compiled knowledge of the heaven and hell dimensions into a single text. The codex discussed geographies, entities, and arcane elements of almost 100 distinct planes of heaven and hell.
This was his prime achievement and his only achievement as it took most of his life to properly study the domains. He does with acclaim and honor and his texts were brought to Mhirriah during the Ozlith Exodus as it also detailed effective ways of combating demonic entities, which the Mhirrians saw as valuable in their war with the Inferbum.
While a footnote in history the text was a major push in the field of evocation and demonology.