1st the items you collect are NO Trade so better make sure you loot on one toon or your still need to loot more to try for the combine. 2. I read if I kill the two other named I would get the item Crystal Harvester Mold but I tried that but nothering happened and both toons left no bodies.
3nd the combine is not NO FAIL no idea what is needed but my i got a skill up of 1 on the fail. and not all the items back. not a no fail combine, failed with skill of 54