Lets say parasite has boots, and one punchdagger. the courier is bringing items containing another punchdagger, neophytes book, and a codex recipe. how does the game decide whether to complete phase boots or a codex upon delivery?
The courier transfers the item on you character in the order you have them placed on him. So if the punchdagger is on the first position in courier's inventory ( ALT+Q) , Ghost Marchers will result.
That's my guess. Please someone correct me if i'm wrong