Bloom of Desecration

You beseech a god of death to strike down enemies. A magical flower of rot begins to sprout from your back. You rise up to 15 feet into the air as the power fills you with strength. Choose any location in range. You launch yourself to that location, landing with a large impact. Movement from this spell does not provoke opportunity attacks. When you land, the bloom on your back explodes with lethal elegance. Each creature within a 30 foot radius of you (excluding you) must roll a constitution saving throw. On a failure, a creature takes 10d10 necrotic damage. This initial burst of damage ignores resistance to necrotic damage. On a success the target takes half damage. Regardless if the creature saves or fails, they take 4d10 necrotic damage at the start of each of their turns until the spell ends.