Blood Mist

Extending your arms outwards you cause all creatures within a 20 foot-radius-sphere to make a Constitution saving throw. On a failure, a creature takes 2d6 Necrotic damage and creates a 10-foot-radius sphere of blood mist centered on themself. On a success, a target takes only half the necrotic damage and does not create a sphere of blood mist. This sphere spreads around corners, and its area is heavily obscured. It lasts for the duration or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it.

Any creature that ends its turn within an area of containing Blood Mist takes 2d6 Necrotic damage. 

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the radius of the initially affected radius increases by 10 feet for each slot level above 1st.