Bone Pulsate

You create a 20-foot-radius sphere of swirling bone fragments centered on yourself. When a creature enters the spell's area for the first time on a turn or starts its turn there, their bones explode and pieces it back together that creature must make a constitution saving throw. The creature takes 1d8 bludgeoning damage and is lightly bleeding on a failed save. on the start of every turn must make a constitution saving throw, or add 1d8 bludgeoning damage until 3 rounds