What's up with that, no matter which side I switch too and if I kill the centurions or the taken they only drop the light energy. Can't complete and went to orbit. Edit, I dropped back in but it started me at the beginning and I don't have it in me to do it all over then possibly have the game F me over again. Maybe save checkpoints next time. Maybe I get the sword this weekend, maybe never, my desire to play this game is less now. 2nd Edit: You have to hit both nodes, without dying--which is different from the 1st encounter with no explanation--before you can spawn the darkness orbs. It's a bad mechanic and poorly explained.