Hypable has a pretty good article up today about which minor characters in OUAT need more episodes. It is simply mind-boggling that OUAT has dropped the ball on Mulan - and while I hadn't been interested in seeing more of Granny previously, I certainly am after reading this article!
But the characters I really want more of are Ruby and Aurora. They weren't much more than set dressing last season, but there is so much more that could be done with their characters. Ruby, especially, is a fan favorite, if the number of requests for her cloak in my costume inbox is any indication! Now that Meghan Ory's slate is reasonably clear again, the showrunners really should snatch her up with a nice contract and give her some juicy bits in part 2 of season 4. I would especially love to see her friendship with Dr. Whale expanded upon.
As for Aurora - last we saw of her she was still pregnant in a gestation that seems to exceed human capabilities (Snow got pregnant after her, and when Snow gave birth at full term, Aurora was still pregnant). We really need to see her baby and learn how Phillip got rescued!
I know fans are cooing over the Hook and Emma sweet moments, but personally I'd like a little less of that mush and a little more fleshing out of some of these other, excellent, characters.