Coordinate "Calldown Mule" with other teammates, only one per team, if already taken, take Lunar blaze once you have learned how to lead a shot for your E stun, or if your team has no disengage, take Quickening Blessing.

Always take Shadowstalk at level 10, free wins, unless you have a coordinated wombocombo team e.g gravbomb Gazlowe, Apocalypse diablo, Valla, kael, Janna, the list goes on (but shadowstalk is still free win).

level 13 is a choice between shrink ray and overflowing light, take shrink ray if the enemy team has particularly troublesome assassins, such as nova, tycus, kerrigan, or falstad (also nazeebo, cuz **** nazeebo), prettymuch anyone with high burst.

level 16 is a tossup between shooting star and trueshot aura, take trusehot if you are NOT CONFIDENT OR EXPERIENCED at landing your stun.

Stormshield is the preferred choice for level 20 talent, you are a support, keep your allies alive, gg.