The sky has fallen and everyone is all hot and bothered about the new daemon factory psychic phase. Everyone is crying that their favorite Deathstar is nerfed or that they lost Jaws of the World Wolf, etc.
I give you one of the new Deathstars.
Along with the just released FAQ:
There you have it, 5-10 FarSeers that do NOT suffer Perils of the Warp. There is no restriction that disallows Jetbikes. They will successfully cast Invisibility along with a handful of other spells.
From your Main force take an Autarch on a jetbike for grenades and other goodies, and to kick it up a notch consider giving one of this unit's FarSeers the Mantle of the Laughing God. for Stealth & Shrouded plus Hit & Run. You can add rune of warding to each FarSeer for a 10 points each to get 5(or more) one shot +2 buffs to deny the witch. Fully loaded the Farseers are 130 points each plus 40 points for the Mantle, so yes its a minimum of 690 points for just the 5 dudes.
Now this list should not win you any friends, but it is far more cost effective ( in terms of real money) than buying a shipping container full of daemons.