If this is true, it makes me wonder if the dreamcatchers are holding memories of past Dark Ones that are now inside Emma’s head and she’s basically infusing the dreamcatchers with various Dark One memories to try and get them out of her head. So we’ll see the First Dark One (or really any Dark One) but through a dreamcatcher.
Ooooh I really like this theory! Another idea I have now that you bring this up, is that since we know you can use a dreamcatcher to see memories, maybe she infuses them with memories from Camelot. Maybe this is how some will get their memories back… I feel like I read a spoiler somewhere that hinted at people getting their memories back at different times.
"To leave an enemy without an answer, say these words to him: Aglaria Pidhol garia Ananus Qepta" and blow in his direction; then he will not know which way he is headed and cannot answer you." - Swedish Trollproverb