Best Support?

Sona paired with a high damage adc can obliterate a lane. Sona has burst with building even a small amount of AP plus her sustain after getting grail is phenomenal at worst. You burst, you heal, you win... so long as you don't go too ham and stay as safe as possible. Leona is amazing with her cc for days. Everything about her kit screams perfection for catching people out and keeping even your derpiest teammates from losing a kill. (pairs amazingly with kaisa as well since you do so much hard cc). Nautilus is by far my favorite out of them all. While not specifically created for supporting, his kit is also much like leona's except that he is a mega tank and you can really abuse lanes early with a godly end game. I play a lot of naut for that reason alone. My duo is a kaisa main so I'm somewhat biased as to what I pick anyways.