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.
Clairvoyance is amazing for support characters because you can use it to get your team gold by pointing out ganks in the woods.
Soul shroud and Aegis provide you with survivability, as well as very good auras for the team. Do not pick up an Aegis if someone on your team is already picking one up. Rush the Rod in that spot or get the new item. Cool down reduction is always a cool thing.
Use your bubble and tornado to save lives. Hit q, pick a direction then hit q again. Sends enemies in the air which can provide time for teammates to get away for when ulti isnt up.