Go to siege of the warmind mission from the dlc. After entering the warmind bunker kill the knights and acolytes in the room. There are a few thrall here also but hard to kill then 2 at a time. Once youve cleared this first room arm your fusion and walk twards the stairs in front of you and to the left. A mob of thralls will start coming tward you back up a bit twards the direction that you came in the bunker. The trall will charge down the stairs turn twards you and rush at you in a strait single file line. BLAST AWAY. There will be about 5 to 6 waves like this just wait and the next one will come. After the waves are over DONT kill the knight at the top of the stairs. If you havent completed the bounty,I usually gat 10-12 each run, go to orbit and come back. If you dont kill the knight youll respawn just outside the door to the bunker amd you can repeat the process. Hope that helps. Happy hunting gaurdian. Oh btw that mission is on Earth

that's weird

Good bit harder to kill two at once when they broke fusions. They Need to change it to shotguns instead of with fusions.