What’s actually very amazing about this pairing is that one half of it doesn’t yet exist in the series (which is probably why I think of it as more of my superficial, oh-my-god-those-fanarts-are-hot ship than a i-will-go-down-with-this-ship ship— okay enough I’ve abused the word ‘ship’ too much).
So everything is fanon. And while I have not explored this pairing quite enough to really have a solidified head canon— what are they? The darker equivalent of Johnlock? Psycho boyfriends? Mutually-manipulative, sex-positive boss and gun-for-hire? Something else entirely?— among any of my ships, I really would have to admit that this is definitely sexier.