To get Deepsighted Resonance weapons in Destiny 2, you will need to progress in the Witch Queen Campain and complete activities.
That said, beyond the initial Glaive we received, we managed to get one Deepsight Weapon by completing The Investigation. You can start the Investigation quest by finding the banner shown below.
The quest will also unlock after speaking to Ikora after you get the first Glaive. During the quest, we received our weapon towards the end when three chests opened up. Shown below is where you can find these chests, but you don't need to worry about missing them.
Related: How to open Umbral Engrams in Destiny 2: The Witch Queen
If you want to get a Deepsight weapon, just start the quest and progress to the end. However, you will need to contend with several bosses. Because of this, we recommend bringing your best weapons along for the ride. You can also get Deepsight Resonance weapons by completing quests in general and various activities on Savathun's Throne World.
To recap, just complete quests and farm dungeons and public events, and you will eventually get a Deepsight Resonance weapon. Once you get a Deepsighted Resonance weapon, you can level it up to extract the weapon's pattern.
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Andrew Vaughan is a Contributing Writer at Pro Game Guides that has written guides on popular RPGs and FPS survival titles for several years. Andrew Vaughan specializes in survival and roleplaying games and has been a lifelong gamer.