NPC IDs affect on items...

[Kisanzi]

I used to believe this on the DC and desperately tried it with Kireek in the forest. But the fact is, is that the rares you find are based on the section ID of the person who created the game. So if you're playing offline quests then regardless of who kills the enemy, you're always going to find the rare for your ID. And the same rules apply for online. If you create the game and someone joins and finds a rare off an enemy they killed, it will still be based on your section ID, not theirs.