I finally got Julian and completed my collection of Goblins!
I did get sidetracked a couple times but now I have all the people who can help grow my Seekers Coins outside of the weekend. Gonna take a brief detour of 50 coins to get the Crystal Kitsunecorn and then try for the Crystal Wyvern and Crystal Naga. I am interested to see if completing part 2 of the Imogen storyline will have her drop the 4 crystals LemracCafe mentioned.
Update: Imogen is still dropping 1 crystal each collection after I craft the Naga. Very rarely, I will get 2 drops but I have never seen more than 2.