Here's a build I use in Quickplay and Ranked. Loadout:
Lunar Connection: 3
Sanctum Of Faith: 3
Full Moon: 3
Crescent: 2
Celestial Body: 4 Legendary Cards:
Life Link(SEI/ONS)
Sacrifice (TDM) Main Item: Nimble

Probably making folks scratch their heads, but it's been working well for me. :T

Edit: Been tinkering more and more with this set. I think I've created a very nice hit and run set that allows Io to enter a situation, do what she has to, and leave.

But I feel as if my healing isn't on par with other support champions. I get around 70k-100k healing. So I might forgo Full Moon in exchange for more Moonlight support. Idk yet.