Hi! I'm Zephyr main and i would like to share to you my Zephyr build :)
For cheaper 2 forma build go to:
Aerodynamic + Aviator gives pretty nice 64% damage reduction when airborne.
You can replace Umbral/Primed mods with their normal counterparts. Then Umbra forma is not necessary.
Aero Vantage for not falling down so quickly when in the air :V and it works nice in the Index as u can for example put this stupid Bursa to sleep.
I would recommend Mirage/Rhino skills for more damage.
Nidus Larva for more crowd control if tornadoes are not enough,
or Wisp Breach Surge as it works nice with tornadoes.
With this build I can easy survive Steel Path and Kuva Liches :v