You call forth the eternal Darkness Sphere from Limbo, where space and time have no meaning.
When a creature starts their Turn in the AOE, they feel the weight of eternal Darkness Sphere dwell on their Soul.
This Magical Darkness requires at least Fiendsight to see through it, and as with most Spells, a Spell must be cast at the same Mana or higher to dispell it up to GMD.
Inky shadows surge, distorting perception. Reality bends and warps, inducing maddening illusions. A realm of chaotic gloom envelops, a manifestation of obscured reality shaped by your arcane command.