Arnzipal’s Black Horror

A roiling black cloud of energy swirls into existence, smoking tendrils of black fire lashing out from it to clutch at those nearby. Each creature in a 400-foot-radius sphere centered on point you choose must make a Constituion saving throw. The sphere spreads around corners. A creature takes 20d10 fire damage on a failed save, or half as much damage on a successful one, each round until they didn't escape the created cloud. Creature in the area of effect count as blinded until the spell is active.