Original Design
Original Design Part 2
One eye kinda like this. Black/Red and unnatural looking.
Robes similar to this, kind of form-fitting at the top but still kinda priestly. A tired or deadened expression like that would be good too.
Robe ref pt 2
Similar color scheme. Lots of white with red highlights. Maybe also the weird hair?
Maybe some fleshy or tentacle-y bits? She controls a gross fleshy monster. Honestly up to you.
Another ref of said fleshy monster, in case you wanted to work in some design aspect for him.