Diagna, (also known as the Orichalc God of the Sideways Blade) was an avatar of the HoonDing (the Yokudan God of Make Way) that achieved permanence as a Redguard sword-god. His "hoary thuggish cult" originated in Yokuda during the Twenty Seven Snake Folk Slaughter. He was instrumental to the defeat of the Lefthanded Elves, as he brought orichalc weapons to the Yokudan people to win the fight. In Tamriel, he led a very tight-knit group of followers, called the Order of Diagna, against the Orcs of Orsinium during the height of their ancient power, but then faded into partial obscurity. He is described as now being little more than a local power spirit of the Dragontail Mountains but he is still worshipped as of the 4th Era, being part of the Eight of the Crowns.
High Kings of Hammerfell are crowned on the Throne of Hegathe by wearing the Diadem of Diagna. Warriors of the Order of Diagna carried armless stone effigies of Diagna during the siege. The Daggerfall Covenant's alliance of the Orcs and Redguards was alleged by the Unveiled Azadiyeh to have inflamed Diagna's very sword-arm with the Crimson Rash of Betrayal.
- The description of the Cobalt Sep Adder originally stated that Diagna was said to have created the lightning-blue Sapphire Adder by passing his orichalc sword over a common Sep Adder when he needed a symbol of Redguard ferocity during the first Siege of Orsinium. It was later changed to remove all mentions of Diagna.
- The Improved Emperor's Guide to Tamriel: Hammerfell — Flaccus Terentius, 2E 581
- Armless Stone Effigy Antiquities Codex from ESO
- Varieties of Faith... — Brother Mikhael Karkuxor of the Imperial College
- Alik'r Bandit's dialogue in Legends
- Varieties of Faith, Crown Redguards — Brother Mikhael Karkuxor of the Imperial College
- The Worthy Ar-Azal, His Deeds
- Plea for Open Eyes — The Unveiled Azadiyeh
- Cobalt Sep Adder pet description in ESO