I was always a fan of the Balewind Vortex,a nd was a bit bummed that it was essentially AoS only. Seemed like a missed opportunity. As such I have converted one to fit my army theme and we've created some test rules for it (below).
Summon Terrain, WC2, any unengaged psyker or brotherhood of psykers (i.e. not locked in combat) may cast the Balewind Vortex. Psykers with the Monstrous Creature or Vehicle type cannot cast the Balewind Vortex. Units on the vortex receive 4+ cover, are immune to nova, template and blast attacks, cannot move, assault, or be tank shocked, moved, or assaulted. The vortex doubles the range of witchfires, blessings, and maledictions for units casting from the vortex. At the start of the controlling player's next turn the vortex automatically dissipates. Any perils of the warp suffered while on the vortex result in a -1 to the roll. Once per turn psykers on the vortex may harness the power of the vortex, capturing warp charge on a 2+, but any doubles result in Perils of the Warp.