Look For Exotic Masterworks
Things to Do After Beating Destiny 2: Warmind
With the Warmind expansion and the latest patch in Destiny 2, players can now hunt down catalysts to unlock a Masterworks version of their favorite Exotic weapons. The Masterworks system was first introduced in Curse of Osiris, but now that the system covers Exotic weapons, they feel even more worthwhile.
How this works is that you have to find a catalyst specific to the Exotic weapon you want to upgrade, and then complete a quest to unlock the Masterworks version of the weapon. The tricky part is finding the catalyst itself to start things off. Folks over at the Destiny 2 subreddit have reported being able to find the Crimson catalyst by hitting precision shots with a Hand Cannon, but for the most part, it still seems random and no one has been able to confirm how exactly to get the items.
Don’t make this a priority; just play through the game, do your Strikes and Nightfalls, and see if you get lucky with the catalyst drops.