Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
This is most likely similar to other guides.
I made this one mainly for myself because this is how I like to build my Janna.
Way to play:
-Don't be to bad at the game.
-Lane with someone who is good early game.
PS. I know Heal and Clarity together are bad. If you don't want heal and Clarity then chose Clairvoyance, Flash, Exhaust instead. It's completely up to you. I suggest using Clarity though, it's great for team fights and is also great to stay in your lane.