Obviously I made the Pickle/Crystal relationship, but I'm probably going to get slaughtered for my other ideas. I know lots of people would probably say Treguard/Majida, but I prefer to see Treguard/Lillith. And I also think Majida/Ridolpho would work nicely (<--- Kill me now

And I also know lots of people think Lord Fear/Aesandre, but I disagree completely! (no, you can't use my Keek video as a contradiction point Martin)
I generally think that the best match-up would be Lord Fear/Lissard. Seriously, I'm not the one to bring up gayness, but Lord Fear seems to have a closer relationship to him than to any other of his assistants, and I think this increases greatly when he turns Lissard into Marta as well.
...but that's just my view on this. Anyone else want to state their beliefs?