Why does nobody play Orianna Support?
She feels really good in that role, in my opinion. I max (E) Protect so it works a lot like Nami, with a little more emphasis on damage; She's got good harass combos, can speed up allies or slow the enemy, protects allies with a shield (instead of heal), and provides wombo combo and peel with her Ult. You can almost describe them both saying the same thing.
Orianna has very strong single-target protection with Protect. The mana cost is significantly less than Ebb & Flow (rank 1 is lower and it doesn't increase) and it has a 1 second shorter CD so spamming it is very easy, plus shields are superior to healing in most regards.
Some major pluses are that she can still waveclear as a Support, and she's good at defending herself.
My recommended items are;

