I found that the ogre kills underneath the map are bs. (At least for me. Never got one drop from it.) My first time just killing enemies over and over netted me 2 engrams in about an hour. Heroic public event completions with the ghost mod were useless, too. Lame. However, once enemies stopped spawning for several minutes, I fast traveled and reset the instance. What ended up happening was sword knights (the ones that drop the relic sword upon death) started spawning every minute or two, and were dropping engrams quite frequently. Once they spawned, I didn’t have to fast travel another time. I had several other guardians that hung around the whole time too, and was able to get my Lumina catalyst just about finished. Once those sword knights start appearing, stick it out. You should get it done in no time. Horrible triumph for the title. At least get catalyst kills so it’s not a complete time sink. Just my experience/observations I had today. Hope it helps.