How do I start the quest at the top of a mountain?
Just like the other Crucible tip weapons in Destiny 2, you will need to take a quest from Shaxx. The quest, which is called "The Ascent", requires you to reach the glory rank of the brave, which only needs 200 glory points. This is the easy part of the quest. The next step is where the grinding begins.
The next part of The Ascent asks you to complete a Triumph called "In Pursuit of Honor". To complete this Triumph, you will need to enter the Crucible and gain 750 Grenade Launcher Shots. On top of that, you'll also need 75 double kills and 25 calculated trajectory medals (triple kills). It should be noted that playing in Iron Banner or Competitive will earn you bonus progress, with wins in the first worth double and kills in the second worth triple.
What should I do after completing the triumph?
After completing the Triumph in Pursuit of Honor, you will need to return to the Crucible, but this time you must reach the Glory Rank of the Legendary. It should be noted that achieving Fabled in the Crucible is also part of the triumph of “The Stuff of Myth,” which is a key milestone in acquiring the Recluse machine gun. Fabled requires you to rack up 2100 Glory Points, but luckily earning Glory is a lot easier due to some of the Crucible changes made by Destiny 2's Shadowkeep expansion. Additionally, solo players don't have to be concerned because there is a Freelance Survival playlist that has a maximum game size. Hitting Fabled is the easiest ever, but it can still be a daunting task.
What happens after reaching the legend?
Once you've got all of your Grenade Launcher shots and hit Fabled earning 2100 Glory Points, it's time to head back to Shaxx at the Tower and complete The Ascent quest. He'll give you your own mountain top, which shoots micro missiles instead of grenades. Since you've already reached Fabled by completing this quest, you're almost done with the Recluse quest. To wrap up this quest you need to complete a few more Crucible matches, but what better way to test your new mountaintop?