Bleeding Darkness (UA)

You create an inky void in a 10-foot-radius Sphere at a point you can see above yourself within range. When you cast the spell, magical Darkness pours from the sphere, filling a 10-foot-radius, 40-foot-tall Cylinder originating from the Sphere until the start of your next turn. The Cylinder is Difficult Terrain, and no light—magical or otherwise-can illuminate the area. When the Darkness appears, each creature in the area must succeed on a Constitution saving throw or take 3d8 Cold damage and have the Blinded condition until the end of its next turn. A creature also makes this save when it enters the spell's area for the first time on a turn or ends its turn there. A creature makes this save only once per turn. Until the spell ends, you can take a Magic action to move the Sphere up to 20 feet horizontally and cause the Sphere to pour magical Darkness until the start of your next turn.

Using a Higher-Level Spell Slot: The damage increases by 1d8 for each spell slot level above 3.