Asti's Galaxy Shower

Call upon the power of the Astral God, Asti. Make a d12 roll. If you get a 8 or higher, he hears your plea and summons a vortex. This vortex lasts for 3 rounds, each round firing a giant meteor at all enemies which does 2d20 force damage. To see the vortex, enemies must make an intelligence saving throw w/ a d12. If they get a 7 or higher, they can see the vortex. If they get a 6 or lower, they can't see the vortex. If you get a 7 or lower, he ignores you and nothing will happen, it will also take up your turn. The vortex is unkillable, so they must use healing to keep themselves alive.