The Turinnash is a special rune-covered, red-orange hooded-cloak also known as spirit mantles. The small silver runes covering much of the voluminous garment supposedly protected the mage from lesser magical threats and even, to a limited degree, some demonic powers.
The Vizjerei wore the Turinnash proudly, almost like a badge of office, a mark of superiority.
References
- Diablo: The Kingdom of Shadow - page 8