Next Hextech Mythic Skin?

Hello, I was just wondering what the potential champion candidates for the remaining 2019 Loot-Exclusive skins were? I recently got to 12 gemstones after only having 8 for well over half a year. I don't really have interest in any of the current ones but if I had to choose from this bunch I'm sure I could. I know they have to meet certain prerequisites such as already having a fair number of skins for purchase as well as having received a skin available for direct purchase somewhat recently. I have several unbiased champions in mind as well as one biased but still viable. I would just like to know if i should spend these gemstones now on a skin I'm not thrilled about or continue to hold them wondering if something i'll ever have sheer excitement for is released.