You create a crimson cloud of toxic blood mist that fills a 150-foot radius sphere and lasts for the duration. The mist spreads around corners and is heavily obscured.

When the cloud appears, each creature within it must make a Constitution saving throw. A creature must also make this saving throw when it ends its turn in the area. On a failed saving throw, a creature takes 8d8 poison damage and 8d8 necrotic damage and is poisoned until the spell ends. A poisoned creature repeats the saving throw at the end of each of its turns while it isn't within the cloud, taking damage on a failed save, and ending the effect on itself on a success.

Until the spell ends, at the start of each of your turns, the radius of the sphere increases by 30 feet, up to a maximum of a 300-foot radius. Any creature with blood that has no more than half of its hit points remaining has disadvantage on saving throws against the spell.

Extremely strong wind can disperse the cloud, such as wind from the wind wake spell or the strongest wind created by the control weather spell.

This spell is a Blood spell in addition to its other school.