How I got it, spoilers for moon.
I was doing bounties and turning them in when I got a yellow reward. It told me to turn it into the bounty robot so I did. The bounty robot offered me 3 different bounties. 2 of the bounties sounded like they were for the warlock so I took the one that sounded like it would give me a weapon because I'm a hunter.
The bounty told me to do the summoning pits strike to get a weapon so my friend and I did.
From the strike I got a depleted hand cannon, I turned in the bounty and it gave me another one to charge the gun with energy. I had to kill 500 hive on moon, easy enough.
I turned that in and the bounty updated again, told me to get 500 kills with void damage in multiplayer and that death would slow my progress. I cried.
Turns out it wasn't that hard, each kill was worth 4 and each death was -2 so that didn't take long.
Then the bounty updated again and I was floored. It unlocked a new strike mission right next to the summoning pits. Level 26 with a skull on that made everything more aggressive, all knights and wizards had shields as well as more enemies. The bounty said I had to kill the minions of phogoth (giant lazerbeam ogre) until Xyor spawned.
I took a bit of time to upgrade my armor but eventually I hit 25 and brought 2 level 25 buddies with me to do it.
It was tough, somebody had to sit in a corner just to spawn the other two. The 30 second respawn time was killer, especially when Phogoth and the wizard swarms decided to spawn kill us. Eventually we killed enough minions and a tombship came in and dropped Xyor.
He was just a regular wizard! Yellow and and a bit of health but not too much worse then the other yellow wizards.
Eventually we killed him and the bounty popped up saying to turn it in. We didn't even have to kill Phogoth so our fire team said fuck that and went back to turn it in.
Speaker gave me Thorn, so happy.
I left out a few details but that's the just of it.
Now to level the sucker...
Edit: remembered another detail, it was the epic skull IIRC.