Halo of Spores

Starting at 2nd level, you are surrounded by invisible, necrotic spores that are harmless until you unleash them on a creature nearby. When a creature you can see moves into a space within 10 feet of you or starts its turn there, you can use your reaction to deal 1d4 Necrotic damage to that creature unless it succeeds on a Constitution saving throw against your spell save DC. The Necrotic damage increases to 1d6 at 6th level, 1d8 at 10th level, and 1d10 at 14th level.