Idea for New Mythic Skin!!

I was wondering what new Mythic skin would be released considering Malzahar was released 4 months ago and Renekton was released 2 months ago. So i could only assume that a new Mythic skin could be released in the near future? Considering that Morgana and Kayle's rework has already been teased why not make a Sisters themed Mythic Skin set? I would love to see a Mythic Morgana skin and it would help celebrate their rework/release. Any thoughts on this or who do you think should be the next Exclusive Mythic Skin?