Drognan's Anguish is a Unique Ring in Diablo IV Season 15. It drops from Andariel (Echo of Andariel).
Unique power
Casting Pyromancy Skills Burns you for 5% of your Maximum Life over 10 seconds. You inflict 200-250% increased Burning damage based on how much of your Life is Burning.
Affixes
111 All Resist
+1-2 to Pyromancy Skills (1-2)
Where it drops
Andariel, Maiden of Anguish (Lair Boss loot table)