The Ring of Diablo IV gold the Midnight Sun is not tied to a single quest or storyline. Instead, it is a world drop unique, meaning it can be acquired from various high-level content in the game. However, your odds increase in certain areas:

Nightmare Dungeons – Running high-tier Nightmare Dungeons is one of the most reliable methods of farming for unique rings. These dungeons not only challenge your skills but also provide some of the richest loot pools.

World Bosses – Bosses like Ashava, Avarice, and Duriel have a chance to drop unique jewelry. Since these bosses can be farmed on rotation, they're worth prioritizing when they spawn.

Helltide Events – The Chests of Mysteries that appear in Helltide zones are great farming sources. Spending your Aberrant Cinders on jewelry caches gives you a better chance at pulling rare rings.

Obol Gambling – At the Purveyor of Diablo 4 gold for sale Curiosities, you can spend Murmuring Obols on jewelry caches. Though completely random, it's a good supplemental method for farming.