Ardent Censer?

Aphromoo bought it on Soraka. I'm pretty sure I've seen Adrian buy it on Soraka too. It's also good on Janna and Karma.

I play Lux support, so I buy it too. If your team has champions like or in the top lane, or in the mid lane, and or in the jungle, it's ridiculous. The synergy with anyone who gives a teamwide shield to also give attack speed and on-hit damage to champions like that is very strong.

I was watching LCK the other day, and in the game Faker built it on Karma mid.

It can work amazing for Soraka. She can extend the duration from 6 seconds to 11 seconds.

And on Karma it's fantastic, Mantra + Shield + Windspeaker's + Ardent. Teamwide Shield, attack speed buff, on-hit buff, movespeed buff and AR/MR buff.

I used to build it on Janna, back when it worked on Turrets :(

Soraka and Sona make great use of this, but it's more handy if the adc is a rapid fire type like Kog'Maw, Tristana and Ashe.

I pop that on my Nami to combo with her E. Speed boost, extra atk speed and more dmg. Toss in a bouncing W and they could probably get it again.

It's just that most people don't care about support-type champs or playstyle so people don't really go looking for it too much.