I want to see a COMPLICATED support champion. One where you do have a lot of options to what you can do and the skill ceiling on the champion is extremely high. Where you can play 200+ games on that champion and get better every time.
The only support champion I can think of that is remotely mechanically difficult is Tresh; all the other supports are extremely easy to play which I think is one of the reasons the role is so unpopular. We might all hate the champs like Yasuo, Lee, Riven, Vayne but one of the reason they are so popular is just because of how much flexibility they have in their kit and the improvement you can do on them.